Knowledge (XXG)

Tree automaton

Source 📝

2272: 435:
variables denoting subtrees. That is, members of Δ are here rewrite rules from nodes whose roots are states to nodes whose children's roots are states. A top-down automaton starts in some of its initial states at the root and moves downward along branches of the tree, associating along a run a state
53:
or not. According to how the automaton processes the input tree, finite tree automata can be of two types: (a) bottom up, (b) top down. This is an important issue, as although non-deterministic (ND) top-down and ND bottom-up tree automata are equivalent in expressive power, deterministic top-down
462:
top-down tree automata are less powerful than their bottom-up counterparts, because in a deterministic tree automaton no two transition rules have the same left-hand side. For tree automata, transition rules are rewrite rules; and for top-down ones, the left-hand side will be parent nodes.
463:
Consequently, a deterministic top-down tree automaton will only be able to test for tree properties that are true in all branches, because the choice of the state to write into each child branch is determined at the parent node, without knowing the child branches contents.
54:
automata are strictly less powerful than their deterministic bottom-up counterparts, because tree properties specified by deterministic top-down tree automata can only depend on path properties. (Deterministic bottom-up tree automata are as powerful as ND tree automata.)
2286:
Using the same colorization as above, this example shows how tree automata generalize ordinary string automata. The finite deterministic string automaton shown in the picture accepts all strings of binary digits that denote a multiple of 3. Using the notions from
2404:)))" in the tree automaton setting; this way, strings can be generalized to trees, or terms. The top-down finite tree automaton accepting the set of all terms corresponding to multiples of 3 in binary string notation is then defined by: 3711:
is a tree with one hole (or, correspondingly, a term with one occurrence of one variable). A context is called "trivial" if the tree consists only of the hole node (or, correspondingly, if the term is just the variable). The notation
222:
variables denoting subtrees. That is, members of Δ are rewrite rules from nodes whose childs' roots are states, to nodes whose roots are states. Thus the state of a node is deduced from the states of its children.
455:). Non-deterministic top-down tree automata have the same expressive power as non-deterministic bottom-up ones; the transition rules are simply reversed, and the final states become the initial states. 3955: 3603:
Proceedings of the 35th Annual Meeting of the Association for Computational Linguistics and Eighth Conference of the European Chapter of the Association for Computational Linguistics
258:). Since these transition rules for constant symbols (leaves) do not require a state, no explicitly defined initial states are needed. A bottom-up tree automaton is run on a 4275: 3948: 532:
having arity 2 and all other symbols having arity 0, a bottom-up tree automaton accepting the set of all finite lists of boolean values can be defined as (
739:
In this example, the rules can be understood intuitively as assigning to each term its type in a bottom-up manner; e.g. rule (4) can be read as "A term
3587:
but they are used there (sect. 1.6, proposition 1.6.2, p. 38). They accept the class of path-closed tree languages (sect. 1.8, exercise 1.6, p. 43-44).
3825:
Comon, Hubert; Dauchet, Max; Gilleron, Rémi; Jacquemard, Florent; Lugiez, Denis; Löding, Christof; Tison, Sophie; Tommasi, Marc (November 2008).
4162: 3941: 4332: 3852: 4087: 4177: 4102: 4317: 4270: 4255: 4322: 4131: 2288: 2275: 1348: 119: 4148: 4073: 3627:, sect. 1.4, theorem 1.4.3, p. 31-32) of tree homomorphism is more general than that of the article "tree homomorphism". 3102:
can be vertically tripartited such that arbitrary repetition ("pumping") of the middle part keeps the resulting term in
4245: 4141: 474: 3453: 4327: 4066: 3511: 3109:
For the language of all finite lists of boolean values from the above example, all terms beyond the height limit
36: 4218: 4213: 3300:
The class of recognizable tree languages is closed under union, under complementation, and under intersection.
4299:
Any language in each category is generated by a grammar and by an automaton in the category in the same line.
3516: 3501: 466: 50: 4229: 4167: 4092: 3491: 17: 3058:
if there is at least one transition rule available for every possible symbol-states combination. A state
1142:
Cf. the derivation of the same term from a regular tree grammar corresponding to the automaton, shown at
4172: 4120: 3933: 3505: 43: 4265: 4240: 4097: 4058: 3313: 2956: 1376: 1143: 477:
theory with two successors. Finite tree automata (nondeterministic if top-down) suffice for WS2S.
4250: 4192: 4136: 3927: 3878: 3863: 436:
with each subterm inductively. A tree is accepted if every branch can be gone through this way.
3985: 3848: 2271: 470: 270:
with each subterm. The term is accepted if its root is associated to an accepting state from
266:, starting at all its leaves simultaneously and moving upwards, associating a run state from 4234: 4187: 4154: 4000: 3606: 3497: 4197: 4112: 4079: 3995: 3968: 3964: 3725: 2952: 1333: 96: 3921: 4208: 3990: 3972: 32: 4311: 4293: 469:
extend top-down automata to infinite trees, and can be used to prove decidability of
28: 3650: 3494:- an application of tree automata to prove an algorithmic meta-theorem about graphs 2368:
In the tree automaton setting, the input alphabet is changed such that the symbols
3046:
A linear (that is, arity-preserving) tree homomorphism preserves recognizability.
3903: 4260: 4182: 4107: 259: 3930:- a library for efficient manipulation of non-deterministic tree automata (C++) 3598: 2959:, respectively, each accepting the same language as its automaton counterpart. 3909: 447:) if no two rules from Δ have the same left hand side; otherwise it is called 42:
The following article deals with branching tree automata, which correspond to
3826: 3605:. ACL '98/EACL '98. USA: Association for Computational Linguistics: 468–475. 3456:
for tree automata states that the following three statements are equivalent:
2976:(that is, a tree) is accepted if there exists a reduction that starts from 3610: 3912:- tools for reachability analysis and tree automata calculations (OCaml) 3469:
is the union of some equivalence classes of a congruence of finite index
3405:. It is of finite index if its number of equivalence-classes is finite. 49:
As with classical automata, finite tree automata (FTA) can be either a
3583:
In a strict sense, deterministic top-down automata are not defined by
3883: 3868: 4223: 2270: 100: 3915: 2951:
For comparison purposes, the table gives in column (A) and (D) a
3918:- library for working with finite tree and hedge automata (Java) 309:, Δ), with two differences with bottom-up tree automata. First, 3937: 3113:=2 can be pumped, since they need to contain an occurrence of 1300:
Top-down automaton accepting multiples of 3 in binary notation
246:()); often the empty parentheses are omitted for convenience: 3877:
Engelfriet, Joost (1975). "Tree Automata and Tree Grammars".
4292:
Each category of languages, except those marked by a , is a
3308:
A congruence on the set of all trees over a ranked alphabet
2386:" in the string automaton setting corresponds to the term " 2992:
is a final state. For a top-down automaton, a ground term
2497:
the transitions being as shown in column (C) of the table.
2364:
the transitions being as shown in column (B) of the table.
3862:
Gécseg, Ferenc; Steinby, Magnus (1984). "Tree Automata".
3845:
Foundations of XML Processing: The Tree-Automata Approach
2996:
is accepted if there exists a reduction that starts from
2382:
is used for tree leaves. For example, the binary string "
335:; second, its transition rules are oriented conversely: 2519:)))" is accepted by the following tree automaton run: 3906:- ranked and unranked tree automata libraries (OCaml) 2792:))" leads to following non-accepting automaton run: 99:(i.e., an alphabet whose symbols have an associated 3043:if there exists a tree automaton that accepts it. 2289:Deterministic finite automaton#Formal definition 16:For a different notion of tree automaton, see 3949: 3597:Morawietz, Frank; Cornell, Tom (1997-07-07). 3054:A non-deterministic finite tree automaton is 2925:Since there are no other initial states than 791:, respectively". An accepting example run is 490:Employing coloring to distinguish members of 234:, the above transition rule definition reads 8: 3808: 3796: 3784: 3772: 3733: 3636: 3624: 3584: 3571: 3559: 3547: 3535: 3500:- extend tree automata in the same way that 118:is a set of final states, and Δ is a set of 4271:Counter-free (with aperiodic finite monoid) 3035:is the set of all ground terms accepted by 2948:))" is not accepted by the tree automaton. 2278:accepting multiples of 3 in binary notation 486:Bottom-up automaton accepting boolean lists 3981: 3956: 3942: 3934: 2934:to start an automaton run with, the term " 2376:are both unary, and a nullary symbol, say 1278:Intuitively, this corresponds to the term 324:, the set of its initial states, replaces 3882: 3867: 3828:Tree Automata Techniques and Applications 2972:For a bottom-up automaton, a ground term 3736:, p. 17, gives a formal definition. 3599:"Representing constraints with automata" 3070:such that there exists a reduction from 1303: 3716:means the result of inserting the tree 3528: 2276:Deterministic finite (string) automaton 4163:Linear context-free rewriting language 4088:Linear context-free rewriting systems 3922:Machine-checked tree automata library 3094:Every sufficiently large ground term 39:of more conventional state machines. 7: 1270:by (2), no further rule applicable. 230:=0, that is, for a constant symbol 4296:of the category directly above it. 3799:, sect. 1.3, theorem 1.3.1, p. 30. 3574:, sect. 1.6, theorem 1.6.1, p. 38. 3086:if all its states are accessible. 2485:the set of initial states being { 2442:the ranked input alphabet being { 14: 3843:Hosoya, Haruo (4 November 2010). 3412:, a congruence can be defined by 2919:by 3, no further rule applicable 3098:in a recognizable tree language 2953:(right) regular (string) grammar 2352:the set of final states being { 498:, and using the ranked alphabet 3481:is a congruence of finite index 3463:is a recognizable tree language 64:bottom-up finite tree automaton 3847:. Cambridge University Press. 3066:if there exists a ground term 583:and Δ consisting of the rules 286:top-down finite tree automaton 1: 3763:means the result of stacking 3682:Formally: there is a context 3292:all belong to that language. 1144:Regular tree grammar#Examples 4333:Theoretical computer science 1375: 1362: 1347: 1332: 1323: 1318: 1313: 1308: 3039:. A set of ground terms is 2329:the input alphabet being { 1252: 1238: 1230: 1205: 1197: 1189: 1174: 1166: 1158: 1149:A rejecting example run is 1123: 1115: 1107: 1099: 1085: 1067: 1059: 1045: 1031: 1023: 1005: 997: 983: 975: 967: 942: 928: 920: 912: 904: 879: 871: 863: 855: 847: 832: 824: 816: 808: 800: 439:A tree automaton is called 4349: 4178:Deterministic context-free 4103:Deterministic context-free 3408:For a given tree-language 3050:Completeness and reduction 44:regular languages of trees 31:. Tree automata deal with 15: 4289: 4251:Nondeterministic pushdown 3979: 3666:> 0 depending only on 3512:Alternating tree automata 2916:))))       1131:)))       2769:)))       2412:of states being still { 2340:the initial state being 1296:) not being well-typed. 4318:Trees (data structures) 3686:, a nontrivial context 2778:In contrast, the term " 2501:For example, the tree " 1267:)       728:))       292:is defined as a tuple ( 70:is defined as a tuple ( 51:deterministic automaton 4323:Automata (computation) 4256:Deterministic pushdown 4132:Recursively enumerable 3724:(or, correspondingly, 3639:, sect. 1.1, p. 23-24. 3517:Infinite-tree automata 3031:, by a tree automaton 2279: 467:Infinite-tree automata 18:tree walking automaton 3611:10.3115/976909.979677 3454:Myhill–Nerode theorem 3304:Myhill–Nerode theorem 3012:is an initial state. 2274: 4241:Tree stack automaton 3771:one in another, cf. 3692:, and a ground term 3314:equivalence relation 2957:regular tree grammar 2291:, it is defined by: 475:monadic second-order 91:is a set of states, 4149:range concatenation 4074:range concatenation 3811:, sect. 1.5, p .36. 3787:, sect. 1.2, p. 29. 3585:Comon et al. (2008) 3562:, sect. 1.1, p. 23. 3550:, sect. 1.6, p. 38. 3538:, sect. 1.1, p. 20. 3492:Courcelle's theorem 3759:≥ 0. The notation 3625:Comon et al. (2008 3015:The tree language 2482:)=0, as explained, 2299:of states being { 2280: 1134:by (4), accepted. 35:, rather than the 4305: 4304: 4284: 4283: 4246:Embedded pushdown 4142:Context-sensitive 4067:Context-sensitive 4001:Abstract machines 3986:Chomsky hierarchy 3854:978-1-139-49236-2 3809:Comon et al. 2008 3797:Comon et al. 2008 3785:Comon et al. 2008 3773:Comon et al. 2008 3734:Comon et al. 2008 3720:into the hole of 3637:Comon et al. 2008 3572:Comon et al. 2008 3560:Comon et al. 2008 3548:Comon et al. 2008 3536:Comon et al. 2008 3445:for each context 3288: 3287: 2923: 2922: 2776: 2775: 2284: 2283: 2265: 2264: 2261: 2260: 2053: 2052: 1808: 1807: 1623: 1622: 1431: 1430: 1274: 1273: 1138: 1137: 735: 734: 4340: 4328:Formal languages 4300: 4297: 4261:Visibly pushdown 4235:Thread automaton 4183:Visibly pushdown 4151: 4108:Visibly pushdown 4076: 4063:(no common name) 3982: 3969:formal languages 3958: 3951: 3944: 3935: 3888: 3886: 3873: 3871: 3858: 3839: 3837: 3835: 3812: 3806: 3800: 3794: 3788: 3782: 3776: 3754: 3743: 3737: 3728:the variable to 3706: 3691: 3680: 3674: 3646: 3640: 3634: 3628: 3621: 3615: 3614: 3594: 3588: 3581: 3575: 3569: 3563: 3557: 3551: 3545: 3539: 3533: 3502:word transducers 3498:Tree transducers 3480: 3444: 3426: 3404: 3394: 3351: 3331: 3277: 3271: 3265: 3257: 3251: 3245: 3239: 3233: 3227: 3211: 3205: 3199: 3191: 3185: 3179: 3173: 3157: 3151: 3145: 3137: 3131: 3124: 3123: 3118: 3004:) and ends with 2947: 2941: 2937: 2933: 2913: 2905: 2894: 2886: 2870: 2860: 2854: 2843: 2830: 2820: 2812: 2806: 2795: 2794: 2791: 2785: 2781: 2766: 2756: 2748: 2740: 2722: 2714: 2703: 2695: 2687: 2669: 2659: 2653: 2642: 2634: 2616: 2606: 2598: 2592: 2581: 2566: 2556: 2548: 2540: 2534: 2522: 2521: 2518: 2512: 2508: 2504: 2493: 2481: 2471: 2463: 2455: 2449: 2445: 2438: 2429: 2420: 2403: 2397: 2393: 2389: 2385: 2381: 2375: 2371: 2360: 2348: 2336: 2332: 2325: 2316: 2307: 2267: 2266: 2256: 2247: 2239: 2226: 2217: 2209: 2196: 2187: 2179: 2166: 2157: 2149: 2136: 2127: 2119: 2106: 2097: 2089: 2077: 2067: 2057: 2056: 2048: 2039: 2030: 2026: 2013: 2004: 1995: 1991: 1978: 1969: 1960: 1956: 1943: 1934: 1925: 1921: 1908: 1899: 1890: 1886: 1873: 1864: 1855: 1851: 1839: 1828: 1822: 1812: 1811: 1804: 1792: 1788: 1775: 1763: 1759: 1746: 1734: 1730: 1717: 1705: 1701: 1688: 1676: 1672: 1659: 1647: 1643: 1627: 1626: 1619: 1611: 1603: 1591: 1583: 1575: 1563: 1555: 1547: 1535: 1527: 1519: 1507: 1499: 1491: 1479: 1471: 1463: 1445: 1435: 1434: 1394: 1393: 1304: 1295: 1289: 1283: 1263: 1257: 1249: 1243: 1235: 1216: 1210: 1202: 1194: 1179: 1171: 1163: 1154: 1153: 1128: 1120: 1112: 1104: 1096: 1090: 1072: 1064: 1056: 1050: 1042: 1036: 1028: 1010: 1002: 994: 988: 980: 972: 953: 947: 939: 933: 925: 917: 909: 890: 884: 876: 868: 860: 852: 837: 829: 821: 813: 805: 796: 795: 790: 784: 764: 744: 719: 713: 698: 688: 682: 669: 663: 653: 640: 634: 624: 611: 605: 595: 588: 587: 582: 580: 565: 559: 531: 525: 519: 513: 507: 449:nondeterministic 425: 334: 323: 280: 212: 120:transition rules 117: 4348: 4347: 4343: 4342: 4341: 4339: 4338: 4337: 4308: 4307: 4306: 4301: 4298: 4291: 4285: 4280: 4202: 4146: 4125: 4071: 4052: 3975: 3973:formal grammars 3965:Automata theory 3962: 3900: 3898:Implementations 3895: 3876: 3861: 3855: 3842: 3833: 3831: 3824: 3821: 3816: 3815: 3807: 3803: 3795: 3791: 3783: 3779: 3746: 3744: 3740: 3697: 3687: 3681: 3677: 3647: 3643: 3635: 3631: 3622: 3618: 3596: 3595: 3591: 3582: 3578: 3570: 3566: 3558: 3554: 3546: 3542: 3534: 3530: 3525: 3488: 3479: 3473: 3428: 3422: 3413: 3396: 3392: 3383: 3372: 3363: 3353: 3350: 3341: 3333: 3330: 3323: 3317: 3306: 3298: 3273: 3267: 3261: 3253: 3247: 3241: 3235: 3229: 3223: 3207: 3201: 3195: 3187: 3181: 3175: 3169: 3153: 3147: 3141: 3133: 3127: 3119:. For example, 3114: 3092: 3052: 2970: 2968:Recognizability 2965: 2943: 2939: 2935: 2932: 2926: 2909: 2904: 2898: 2892: 2884: 2866: 2858: 2853: 2847: 2841: 2826: 2818: 2810: 2805: 2799: 2787: 2783: 2779: 2762: 2754: 2746: 2738: 2718: 2713: 2707: 2701: 2693: 2685: 2665: 2657: 2652: 2646: 2640: 2632: 2612: 2604: 2596: 2591: 2585: 2579: 2562: 2554: 2546: 2538: 2533: 2527: 2514: 2510: 2506: 2502: 2492: 2486: 2477: 2469: 2461: 2451: 2447: 2443: 2437: 2431: 2428: 2422: 2419: 2413: 2399: 2395: 2391: 2387: 2383: 2377: 2373: 2369: 2359: 2353: 2347: 2341: 2334: 2330: 2324: 2318: 2315: 2309: 2306: 2300: 2255: 2249: 2245: 2238: 2232: 2225: 2219: 2215: 2208: 2202: 2195: 2189: 2185: 2178: 2172: 2165: 2159: 2155: 2148: 2142: 2135: 2129: 2125: 2118: 2112: 2105: 2099: 2095: 2088: 2082: 2073: 2066: 2060: 2047: 2041: 2037: 2028: 2025: 2019: 2012: 2006: 2002: 1993: 1990: 1984: 1977: 1971: 1967: 1958: 1955: 1949: 1942: 1936: 1932: 1923: 1920: 1914: 1907: 1901: 1897: 1888: 1885: 1879: 1872: 1866: 1862: 1853: 1850: 1844: 1835: 1824: 1821: 1815: 1803: 1797: 1790: 1787: 1781: 1774: 1768: 1761: 1758: 1752: 1745: 1739: 1732: 1729: 1723: 1716: 1710: 1703: 1700: 1694: 1687: 1681: 1674: 1671: 1665: 1658: 1652: 1645: 1642: 1636: 1618: 1612: 1609: 1602: 1596: 1590: 1584: 1581: 1574: 1568: 1562: 1556: 1553: 1546: 1540: 1534: 1528: 1525: 1518: 1512: 1506: 1500: 1497: 1490: 1484: 1478: 1472: 1469: 1462: 1456: 1444: 1438: 1385: 1380: 1370: 1366: 1357: 1352: 1342: 1337: 1302: 1291: 1285: 1279: 1259: 1253: 1245: 1239: 1231: 1212: 1206: 1198: 1190: 1175: 1167: 1159: 1124: 1116: 1108: 1100: 1092: 1086: 1068: 1060: 1052: 1046: 1038: 1032: 1024: 1006: 998: 990: 984: 976: 968: 949: 943: 935: 929: 921: 913: 905: 886: 880: 872: 864: 856: 848: 833: 825: 817: 809: 801: 786: 780: 778: 771: 760: 758: 751: 740: 727: 723: 715: 709: 702: 694: 692: 684: 678: 665: 659: 649: 636: 630: 620: 607: 601: 591: 576: 574: 561: 555: 550: 548: 527: 521: 515: 509: 503: 488: 483: 434: 420: 400: 394: 385: 376: 369: 358: 349: 333: 325: 318: 310: 308: 279: 271: 221: 207: 187: 181: 172: 157: 148: 139: 132: 112: 104: 97:ranked alphabet 86: 60: 33:tree structures 21: 12: 11: 5: 4346: 4344: 4336: 4335: 4330: 4325: 4320: 4310: 4309: 4303: 4302: 4290: 4287: 4286: 4282: 4281: 4279: 4278: 4276:Acyclic finite 4273: 4268: 4263: 4258: 4253: 4248: 4243: 4237: 4232: 4227: 4226:Turing Machine 4221: 4219:Linear-bounded 4216: 4211: 4209:Turing machine 4205: 4203: 4201: 4200: 4195: 4190: 4185: 4180: 4175: 4170: 4168:Tree-adjoining 4165: 4160: 4157: 4152: 4144: 4139: 4134: 4128: 4126: 4124: 4123: 4118: 4115: 4110: 4105: 4100: 4095: 4093:Tree-adjoining 4090: 4085: 4082: 4077: 4069: 4064: 4061: 4055: 4053: 4051: 4050: 4047: 4044: 4041: 4038: 4035: 4032: 4029: 4026: 4023: 4020: 4017: 4014: 4011: 4007: 4004: 4003: 3998: 3993: 3988: 3980: 3977: 3976: 3963: 3961: 3960: 3953: 3946: 3938: 3932: 3931: 3925: 3919: 3913: 3907: 3899: 3896: 3894: 3893:External links 3891: 3890: 3889: 3874: 3859: 3853: 3840: 3820: 3817: 3814: 3813: 3801: 3789: 3777: 3738: 3707:. A "context" 3675: 3641: 3629: 3623:The notion in 3616: 3589: 3576: 3564: 3552: 3540: 3527: 3526: 3524: 3521: 3520: 3519: 3514: 3509: 3495: 3487: 3484: 3483: 3482: 3475: 3470: 3464: 3418: 3388: 3381: 3368: 3361: 3346: 3337: 3328: 3321: 3305: 3302: 3297: 3294: 3290: 3289: 3286: 3285: 3282: 3279: 3259: 3220: 3219: 3216: 3213: 3193: 3166: 3165: 3162: 3159: 3139: 3091: 3088: 3082:). An NFTA is 3051: 3048: 2980:and ends with 2969: 2966: 2964: 2961: 2930: 2921: 2920: 2917: 2914: 2907: 2902: 2896: 2890: 2888: 2882: 2878: 2877: 2874: 2871: 2864: 2862: 2856: 2851: 2845: 2839: 2835: 2834: 2831: 2824: 2822: 2816: 2814: 2808: 2803: 2774: 2773: 2770: 2767: 2760: 2758: 2752: 2750: 2744: 2742: 2736: 2734: 2730: 2729: 2726: 2723: 2716: 2711: 2705: 2699: 2697: 2691: 2689: 2683: 2681: 2677: 2676: 2673: 2670: 2663: 2661: 2655: 2650: 2644: 2638: 2636: 2630: 2628: 2624: 2623: 2620: 2617: 2610: 2608: 2602: 2600: 2594: 2589: 2583: 2577: 2575: 2571: 2570: 2567: 2560: 2558: 2552: 2550: 2544: 2542: 2536: 2531: 2525: 2499: 2498: 2495: 2490: 2483: 2440: 2435: 2426: 2417: 2366: 2365: 2362: 2357: 2350: 2345: 2338: 2327: 2322: 2313: 2304: 2282: 2281: 2263: 2262: 2259: 2258: 2253: 2243: 2240: 2236: 2229: 2228: 2223: 2213: 2210: 2206: 2199: 2198: 2193: 2183: 2180: 2176: 2169: 2168: 2163: 2153: 2150: 2146: 2139: 2138: 2133: 2123: 2120: 2116: 2109: 2108: 2103: 2093: 2090: 2086: 2079: 2078: 2071: 2068: 2064: 2054: 2051: 2050: 2045: 2035: 2032: 2023: 2016: 2015: 2010: 2000: 1997: 1988: 1981: 1980: 1975: 1965: 1962: 1953: 1946: 1945: 1940: 1930: 1927: 1918: 1911: 1910: 1905: 1895: 1892: 1883: 1876: 1875: 1870: 1860: 1857: 1848: 1841: 1840: 1833: 1830: 1819: 1809: 1806: 1805: 1801: 1794: 1785: 1777: 1776: 1772: 1765: 1756: 1748: 1747: 1743: 1736: 1727: 1719: 1718: 1714: 1707: 1698: 1690: 1689: 1685: 1678: 1669: 1661: 1660: 1656: 1649: 1640: 1632: 1631: 1624: 1621: 1620: 1616: 1607: 1604: 1600: 1593: 1592: 1588: 1579: 1576: 1572: 1565: 1564: 1560: 1551: 1548: 1544: 1537: 1536: 1532: 1523: 1520: 1516: 1509: 1508: 1504: 1495: 1492: 1488: 1481: 1480: 1476: 1467: 1464: 1460: 1453: 1452: 1449: 1446: 1442: 1432: 1429: 1428: 1424: 1423: 1419: 1418: 1414: 1413: 1409: 1408: 1404: 1403: 1399: 1398: 1390: 1389: 1374: 1361: 1346: 1331: 1328: 1327: 1322: 1317: 1312: 1307: 1301: 1298: 1276: 1275: 1272: 1271: 1268: 1265: 1251: 1237: 1229: 1225: 1224: 1221: 1218: 1204: 1196: 1188: 1184: 1183: 1180: 1173: 1165: 1157: 1140: 1139: 1136: 1135: 1132: 1129: 1122: 1114: 1106: 1098: 1084: 1080: 1079: 1076: 1073: 1066: 1058: 1044: 1030: 1022: 1018: 1017: 1014: 1011: 1004: 996: 982: 974: 966: 962: 961: 958: 955: 941: 927: 919: 911: 903: 899: 898: 895: 892: 878: 870: 862: 854: 846: 842: 841: 838: 831: 823: 815: 807: 799: 776: 769: 756: 749: 737: 736: 733: 732: 729: 725: 721: 707: 704: 700: 690: 675: 674: 671: 657: 654: 646: 645: 642: 628: 625: 617: 616: 613: 599: 596: 570: 544: 526:(.,.) }, with 487: 484: 482: 479: 430: 416: 390: 381: 374: 367: 354: 347: 329: 314: 304: 275: 217: 203: 177: 170: 153: 144: 137: 130: 108: 82: 59: 56: 25:tree automaton 13: 10: 9: 6: 4: 3: 2: 4345: 4334: 4331: 4329: 4326: 4324: 4321: 4319: 4316: 4315: 4313: 4295: 4294:proper subset 4288: 4277: 4274: 4272: 4269: 4267: 4264: 4262: 4259: 4257: 4254: 4252: 4249: 4247: 4244: 4242: 4238: 4236: 4233: 4231: 4228: 4225: 4222: 4220: 4217: 4215: 4212: 4210: 4207: 4206: 4204: 4199: 4196: 4194: 4191: 4189: 4186: 4184: 4181: 4179: 4176: 4174: 4171: 4169: 4166: 4164: 4161: 4158: 4156: 4153: 4150: 4145: 4143: 4140: 4138: 4135: 4133: 4130: 4129: 4127: 4122: 4121:Non-recursive 4119: 4116: 4114: 4111: 4109: 4106: 4104: 4101: 4099: 4096: 4094: 4091: 4089: 4086: 4083: 4081: 4078: 4075: 4070: 4068: 4065: 4062: 4060: 4057: 4056: 4054: 4048: 4045: 4042: 4039: 4036: 4033: 4030: 4027: 4024: 4021: 4018: 4015: 4012: 4009: 4008: 4006: 4005: 4002: 3999: 3997: 3994: 3992: 3989: 3987: 3984: 3983: 3978: 3974: 3970: 3966: 3959: 3954: 3952: 3947: 3945: 3940: 3939: 3936: 3929: 3926: 3923: 3920: 3917: 3914: 3911: 3908: 3905: 3902: 3901: 3897: 3892: 3885: 3880: 3875: 3870: 3865: 3860: 3856: 3850: 3846: 3841: 3830: 3829: 3823: 3822: 3818: 3810: 3805: 3802: 3798: 3793: 3790: 3786: 3781: 3778: 3775:, p. 17. 3774: 3770: 3766: 3762: 3758: 3753: 3749: 3742: 3739: 3735: 3731: 3727: 3726:instantiating 3723: 3719: 3715: 3710: 3704: 3700: 3695: 3690: 3685: 3679: 3676: 3673: 3669: 3665: 3661: 3657: 3653: 3652: 3645: 3642: 3638: 3633: 3630: 3626: 3620: 3617: 3612: 3608: 3604: 3600: 3593: 3590: 3586: 3580: 3577: 3573: 3568: 3565: 3561: 3556: 3553: 3549: 3544: 3541: 3537: 3532: 3529: 3522: 3518: 3515: 3513: 3510: 3507: 3506:word automata 3503: 3499: 3496: 3493: 3490: 3489: 3485: 3478: 3472:the relation 3471: 3468: 3465: 3462: 3459: 3458: 3457: 3455: 3450: 3448: 3443: 3439: 3435: 3431: 3425: 3421: 3416: 3411: 3406: 3403: 3399: 3391: 3387: 3380: 3376: 3371: 3367: 3360: 3356: 3349: 3345: 3340: 3336: 3327: 3320: 3315: 3311: 3303: 3301: 3295: 3293: 3283: 3280: 3276: 3270: 3264: 3260: 3256: 3250: 3244: 3238: 3232: 3226: 3222: 3221: 3217: 3214: 3210: 3204: 3198: 3194: 3190: 3184: 3178: 3172: 3168: 3167: 3163: 3160: 3156: 3150: 3144: 3140: 3136: 3130: 3126: 3125: 3122: 3121: 3120: 3117: 3112: 3107: 3105: 3101: 3097: 3090:Pumping lemma 3089: 3087: 3085: 3081: 3077: 3073: 3069: 3065: 3061: 3057: 3049: 3047: 3044: 3042: 3038: 3034: 3030: 3026: 3022: 3018: 3013: 3011: 3007: 3003: 2999: 2995: 2991: 2987: 2983: 2979: 2975: 2967: 2962: 2960: 2958: 2954: 2949: 2946: 2929: 2918: 2915: 2912: 2908: 2901: 2897: 2891: 2889: 2883: 2880: 2879: 2875: 2872: 2869: 2865: 2863: 2857: 2850: 2846: 2840: 2837: 2836: 2832: 2829: 2825: 2823: 2817: 2815: 2809: 2802: 2797: 2796: 2793: 2790: 2771: 2768: 2765: 2761: 2759: 2753: 2751: 2745: 2743: 2737: 2735: 2732: 2731: 2727: 2724: 2721: 2717: 2710: 2706: 2700: 2698: 2692: 2690: 2684: 2682: 2679: 2678: 2674: 2671: 2668: 2664: 2662: 2656: 2649: 2645: 2639: 2637: 2631: 2629: 2626: 2625: 2621: 2618: 2615: 2611: 2609: 2603: 2601: 2595: 2588: 2584: 2578: 2576: 2573: 2572: 2568: 2565: 2561: 2559: 2553: 2551: 2545: 2543: 2537: 2530: 2526: 2524: 2523: 2520: 2517: 2496: 2489: 2484: 2480: 2475: 2467: 2459: 2454: 2441: 2434: 2425: 2416: 2411: 2407: 2406: 2405: 2402: 2380: 2363: 2356: 2351: 2344: 2339: 2328: 2321: 2312: 2303: 2298: 2294: 2293: 2292: 2290: 2277: 2273: 2269: 2268: 2252: 2244: 2241: 2235: 2231: 2230: 2222: 2214: 2211: 2205: 2201: 2200: 2192: 2184: 2181: 2175: 2171: 2170: 2162: 2154: 2151: 2145: 2141: 2140: 2132: 2124: 2121: 2115: 2111: 2110: 2102: 2094: 2091: 2085: 2081: 2080: 2076: 2072: 2069: 2063: 2059: 2058: 2055: 2044: 2036: 2033: 2022: 2018: 2017: 2009: 2001: 1998: 1987: 1983: 1982: 1974: 1966: 1963: 1952: 1948: 1947: 1939: 1931: 1928: 1917: 1913: 1912: 1904: 1896: 1893: 1882: 1878: 1877: 1869: 1861: 1858: 1847: 1843: 1842: 1838: 1834: 1831: 1827: 1818: 1814: 1813: 1810: 1800: 1795: 1784: 1779: 1778: 1771: 1766: 1755: 1750: 1749: 1742: 1737: 1726: 1721: 1720: 1713: 1708: 1697: 1692: 1691: 1684: 1679: 1668: 1663: 1662: 1655: 1650: 1639: 1634: 1633: 1629: 1628: 1625: 1615: 1608: 1605: 1599: 1595: 1594: 1587: 1580: 1577: 1571: 1567: 1566: 1559: 1552: 1549: 1543: 1539: 1538: 1531: 1524: 1521: 1515: 1511: 1510: 1503: 1496: 1493: 1487: 1483: 1482: 1475: 1468: 1465: 1459: 1455: 1454: 1450: 1447: 1441: 1437: 1436: 1433: 1426: 1425: 1421: 1420: 1416: 1415: 1411: 1410: 1406: 1405: 1401: 1400: 1396: 1395: 1392: 1391: 1388: 1384: 1383: 1379: 1373: 1369: 1365: 1360: 1356: 1355: 1351: 1345: 1341: 1340: 1336: 1330: 1329: 1326: 1321: 1316: 1311: 1306: 1305: 1299: 1297: 1294: 1288: 1282: 1269: 1266: 1262: 1256: 1248: 1242: 1234: 1227: 1226: 1222: 1219: 1215: 1209: 1201: 1193: 1186: 1185: 1181: 1178: 1170: 1162: 1156: 1155: 1152: 1151: 1150: 1147: 1145: 1133: 1130: 1127: 1119: 1111: 1103: 1095: 1089: 1082: 1081: 1077: 1074: 1071: 1063: 1055: 1049: 1041: 1035: 1027: 1020: 1019: 1015: 1012: 1009: 1001: 993: 987: 979: 971: 964: 963: 959: 956: 952: 946: 938: 932: 924: 916: 908: 901: 900: 896: 893: 889: 883: 875: 867: 859: 851: 844: 843: 839: 836: 828: 820: 812: 804: 798: 797: 794: 793: 792: 789: 783: 775: 768: 763: 755: 748: 743: 730: 718: 712: 708: 705: 697: 687: 681: 677: 676: 672: 668: 662: 658: 655: 652: 648: 647: 643: 639: 633: 629: 626: 623: 619: 618: 614: 610: 604: 600: 597: 594: 590: 589: 586: 585: 584: 579: 573: 569: 564: 558: 553: 547: 543: 539: 535: 530: 524: 518: 512: 506: 501: 497: 493: 485: 480: 478: 476: 472: 468: 464: 461: 460:deterministic 458:In contrast, 456: 454: 450: 446: 443:(abbreviated 442: 441:deterministic 437: 433: 429: 424: 419: 415: 411: 407: 403: 398: 393: 389: 384: 380: 373: 366: 362: 357: 353: 346: 342: 338: 332: 328: 322: 317: 313: 307: 303: 299: 295: 291: 287: 282: 278: 274: 269: 265: 261: 257: 253: 249: 245: 241: 237: 233: 229: 224: 220: 216: 211: 206: 202: 198: 194: 190: 185: 180: 176: 169: 165: 161: 156: 152: 147: 143: 136: 129: 125: 121: 116: 111: 107: 102: 98: 94: 90: 85: 81: 77: 73: 69: 65: 57: 55: 52: 47: 45: 40: 38: 34: 30: 29:state machine 27:is a type of 26: 19: 4230:Nested stack 4173:Context-free 4098:Context-free 4059:Unrestricted 3844: 3832:. Retrieved 3827: 3804: 3792: 3780: 3768: 3764: 3760: 3756: 3751: 3747: 3741: 3729: 3721: 3717: 3713: 3708: 3702: 3698: 3693: 3688: 3683: 3678: 3671: 3667: 3663: 3659: 3655: 3649: 3644: 3632: 3619: 3602: 3592: 3579: 3567: 3555: 3543: 3531: 3476: 3466: 3460: 3451: 3446: 3441: 3437: 3433: 3429: 3423: 3419: 3414: 3409: 3407: 3401: 3397: 3395:, for every 3389: 3385: 3378: 3374: 3369: 3365: 3358: 3354: 3347: 3343: 3338: 3334: 3332:and ... and 3325: 3318: 3309: 3307: 3299: 3291: 3274: 3268: 3262: 3254: 3248: 3242: 3236: 3230: 3224: 3208: 3202: 3196: 3188: 3182: 3176: 3170: 3154: 3148: 3142: 3134: 3128: 3115: 3110: 3108: 3103: 3099: 3095: 3093: 3083: 3079: 3075: 3071: 3067: 3063: 3059: 3055: 3053: 3045: 3041:recognizable 3040: 3036: 3032: 3028: 3024: 3020: 3016: 3014: 3009: 3005: 3001: 2997: 2993: 2989: 2985: 2981: 2977: 2973: 2971: 2950: 2944: 2927: 2924: 2910: 2899: 2867: 2848: 2827: 2800: 2788: 2777: 2763: 2719: 2708: 2666: 2647: 2613: 2586: 2563: 2528: 2515: 2500: 2487: 2478: 2473: 2465: 2457: 2452: 2432: 2423: 2414: 2409: 2400: 2378: 2367: 2354: 2342: 2319: 2310: 2301: 2296: 2285: 2250: 2233: 2220: 2203: 2190: 2173: 2160: 2143: 2130: 2113: 2100: 2083: 2074: 2061: 2042: 2020: 2007: 1985: 1972: 1950: 1937: 1915: 1902: 1880: 1867: 1845: 1836: 1825: 1816: 1798: 1782: 1769: 1753: 1740: 1724: 1711: 1695: 1682: 1666: 1653: 1637: 1613: 1597: 1585: 1569: 1557: 1541: 1529: 1513: 1501: 1485: 1473: 1457: 1439: 1386: 1381: 1377: 1371: 1367: 1363: 1358: 1353: 1349: 1343: 1338: 1334: 1324: 1319: 1314: 1309: 1292: 1286: 1280: 1277: 1260: 1254: 1246: 1240: 1232: 1213: 1207: 1199: 1191: 1176: 1168: 1160: 1148: 1141: 1125: 1117: 1109: 1101: 1093: 1087: 1069: 1061: 1053: 1047: 1039: 1033: 1025: 1007: 999: 991: 985: 977: 969: 950: 944: 936: 930: 922: 914: 906: 887: 881: 873: 865: 857: 849: 834: 826: 818: 810: 802: 787: 781: 773: 766: 761: 753: 746: 741: 738: 716: 710: 695: 685: 679: 666: 660: 650: 637: 631: 621: 608: 602: 592: 577: 571: 567: 562: 556: 551: 545: 541: 537: 533: 528: 522: 516: 510: 504: 499: 495: 491: 489: 465: 459: 457: 452: 448: 444: 440: 438: 431: 427: 422: 417: 413: 409: 405: 401: 396: 391: 387: 382: 378: 371: 364: 360: 355: 351: 344: 340: 336: 330: 326: 320: 315: 311: 305: 301: 297: 293: 289: 285: 283: 276: 272: 267: 263: 255: 251: 247: 243: 239: 235: 231: 227: 225: 218: 214: 209: 204: 200: 196: 192: 188: 183: 178: 174: 167: 163: 159: 154: 150: 145: 141: 134: 127: 123: 122:of the form 114: 109: 105: 92: 88: 87:, Δ), where 83: 79: 75: 71: 67: 63: 61: 48: 41: 24: 22: 4239:restricted 3924:(Isabelle ) 3834:11 February 1372:transitions 1359:transitions 765:, provided 759:) has type 395:)), for an 260:ground term 182:)), for an 58:Definitions 4312:Categories 3884:1510.02036 3869:1509.06233 3819:References 3767:copies of 3745:Formally: 3696:such that 3648:Formally: 3316:such that 3064:accessible 3029:recognized 2963:Properties 549:, Δ) with 4193:Star-free 4147:Positive 4137:Decidable 4072:Positive 3996:Languages 3670:, not on 2988:), where 1368:automaton 1354:automaton 779:has type 673:(3), and 3991:Grammars 3755:for all 3689:C′ 3486:See also 3352:implies 3056:complete 3025:accepted 3008:, where 2955:, and a 2472:)=1 and 2456:}, with 2408:the set 2295:the set 481:Examples 4214:Decider 4188:Regular 4155:Indexed 4113:Regular 4080:Indexed 3662:, with 3658:) > 3504:extend 3296:Closure 3084:reduced 1630:  1382:grammar 1339:grammar 1223:by (1) 1078:by (1) 1016:by (4) 960:by (2) 897:by (3) 37:strings 4266:Finite 4198:Finite 4043:Type-3 4034:Type-2 4016:Type-1 4010:Type-0 3916:LETHAL 3910:Timbuk 3904:Grappa 3851:  3651:height 3312:is an 3284:, ... 2494:}, and 2361:}, and 1350:String 1335:String 473:, the 426:, and 377:),..., 359:)) → 213:, and 140:),..., 4224:PTIME 3879:arXiv 3864:arXiv 3523:Notes 3384:,..., 3364:,..., 3255:false 3243:false 3231:false 3189:false 3177:false 3135:false 3027:, or 2876:by 2 2772:by 0 2728:by 1 2675:by 4 2622:by 2 2569:)))) 2474:Arity 2466:Arity 2458:Arity 2049:(x)) 2014:(x)) 1979:(x)) 1944:(x)) 1909:(x)) 1874:(x)) 1387:rules 1344:rules 1287:false 1247:false 1200:false 1169:false 1102:false 1088:BList 1048:BList 1040:false 986:BList 978:false 945:BList 915:false 882:BList 858:false 811:false 788:BList 762:BList 731:(4). 711:BList 696:BList 661:BList 644:(2), 615:(1), 609:false 593:false 578:BList 563:BList 505:false 399:-ary 350:,..., 288:over 262:over 238:() → 186:-ary 173:,..., 158:)) → 101:arity 95:is a 66:over 3971:and 3928:VATA 3849:ISBN 3836:2014 3750:] ∈ 3452:The 3373:) ≡ 3281:))) 3269:true 3263:cons 3249:cons 3237:cons 3225:cons 3203:true 3197:cons 3183:cons 3171:cons 3149:true 3143:cons 3129:cons 3116:cons 2873:)))) 2833:))) 2725:)))) 2672:)))) 2619:)))) 2372:and 2031:(x)) 1996:(x)) 1961:(x)) 1926:(x)) 1891:(x)) 1856:(x)) 1378:Tree 1364:Tree 1293:true 1281:cons 1261:true 1255:Bool 1241:Bool 1233:cons 1214:true 1208:Bool 1192:cons 1177:true 1161:cons 1118:true 1110:cons 1094:cons 1075:))) 1062:true 1054:cons 1034:Bool 1026:cons 1013:))) 1000:true 992:cons 970:cons 937:true 931:Bool 923:cons 907:cons 874:true 866:cons 850:cons 827:true 819:cons 803:cons 785:and 782:Bool 772:and 742:cons 717:cons 686:Bool 680:cons 638:true 632:Bool 622:true 603:Bool 575:= { 557:Bool 554:= { 529:cons 523:cons 511:true 494:and 453:NFTA 445:DFTA 226:For 3732:). 3607:doi 3427:if 3275:nil 3215:)) 3209:nil 3155:nil 3074:to 3062:is 2945:nil 2911:nil 2868:nil 2828:nil 2798:⇒ 2789:nil 2764:nil 2720:nil 2667:nil 2614:nil 2564:nil 2516:nil 2479:nil 2453:nil 2401:nil 2384:110 2379:nil 2075:nil 1837:nil 1826:nil 1325:(D) 1320:(C) 1315:(B) 1310:(A) 1250:), 1126:nil 1070:nil 1043:), 1008:nil 957:)) 951:nil 940:), 894:)) 888:nil 840:)) 835:nil 667:nil 651:nil 566:}, 517:nil 502:={ 471:S2S 103:), 4314:: 3967:: 3701:= 3601:. 3449:. 3440:∈ 3436:⇔ 3432:∈ 3400:∈ 3342:≡ 3324:≡ 3278:) 3258:, 3218:, 3212:) 3192:, 3164:, 3161:) 3158:) 3138:, 3106:. 3023:) 2464:)= 2450:, 2446:, 2439:}, 2430:, 2421:, 2337:}, 2333:, 2326:}, 2317:, 2308:, 2257:) 2227:) 2197:) 2167:) 2137:) 2107:) 1796:= 1780:δ( 1767:= 1751:δ( 1738:= 1722:δ( 1709:= 1693:δ( 1680:= 1664:δ( 1651:= 1635:δ( 1451:ε 1427:6 1422:5 1417:4 1412:3 1407:2 1402:1 1397:0 1264:) 1236:( 1228:⇒ 1220:) 1217:) 1203:, 1195:( 1187:⇒ 1182:) 1172:, 1164:( 1146:. 1121:, 1113:( 1105:, 1097:( 1083:⇒ 1065:, 1057:( 1029:( 1021:⇒ 1003:, 995:( 981:, 973:( 965:⇒ 954:) 926:( 918:, 910:( 902:⇒ 891:) 877:, 869:( 861:, 853:( 845:⇒ 830:, 822:( 814:, 806:( 724:,x 720:(x 703:)) 699:(x 693:), 689:(x 581:}, 540:, 536:, 421:∈ 412:, 408:, 404:∈ 319:⊆ 300:, 296:, 284:A 281:. 250:→ 208:∈ 199:, 195:, 191:∈ 113:⊆ 78:, 74:, 62:A 46:. 23:A 4159:— 4117:— 4084:— 4049:— 4046:— 4040:— 4037:— 4031:— 4028:— 4025:— 4022:— 4019:— 4013:— 3957:e 3950:t 3943:v 3887:. 3881:: 3872:. 3866:: 3857:. 3838:. 3769:C 3765:n 3761:C 3757:n 3752:L 3748:C 3730:t 3722:C 3718:t 3714:C 3709:C 3705:] 3703:C 3699:t 3694:u 3684:C 3672:t 3668:L 3664:k 3660:k 3656:t 3654:( 3613:. 3609:: 3508:. 3477:L 3474:≡ 3467:L 3461:L 3447:C 3442:L 3438:C 3434:L 3430:C 3424:v 3420:L 3417:≡ 3415:u 3410:L 3402:F 3398:f 3393:) 3390:n 3386:v 3382:1 3379:v 3377:( 3375:f 3370:n 3366:u 3362:1 3359:u 3357:( 3355:f 3348:n 3344:v 3339:n 3335:u 3329:1 3326:v 3322:1 3319:u 3310:F 3272:, 3266:( 3252:( 3246:, 3240:( 3234:, 3228:( 3206:, 3200:( 3186:( 3180:, 3174:( 3152:, 3146:( 3132:( 3111:k 3104:L 3100:L 3096:t 3080:t 3078:( 3076:q 3072:t 3068:t 3060:q 3037:A 3033:A 3021:A 3019:( 3017:L 3010:q 3006:t 3002:t 3000:( 2998:q 2994:t 2990:q 2986:t 2984:( 2982:q 2978:t 2974:t 2942:( 2940:0 2938:( 2936:1 2931:0 2928:S 2906:( 2903:2 2900:S 2895:( 2893:0 2887:( 2885:1 2881:⇒ 2861:( 2859:0 2855:( 2852:1 2849:S 2844:( 2842:1 2838:⇒ 2821:( 2819:0 2813:( 2811:1 2807:( 2804:0 2801:S 2786:( 2784:0 2782:( 2780:1 2757:( 2755:0 2749:( 2747:1 2741:( 2739:1 2733:⇒ 2715:( 2712:0 2709:S 2704:( 2702:0 2696:( 2694:1 2688:( 2686:1 2680:⇒ 2660:( 2658:0 2654:( 2651:0 2648:S 2643:( 2641:1 2635:( 2633:1 2627:⇒ 2607:( 2605:0 2599:( 2597:1 2593:( 2590:1 2587:S 2582:( 2580:1 2574:⇒ 2557:( 2555:0 2549:( 2547:1 2541:( 2539:1 2535:( 2532:0 2529:S 2513:( 2511:0 2509:( 2507:1 2505:( 2503:1 2491:0 2488:S 2476:( 2470:1 2468:( 2462:0 2460:( 2448:1 2444:0 2436:2 2433:S 2427:1 2424:S 2418:0 2415:S 2410:Q 2398:( 2396:0 2394:( 2392:1 2390:( 2388:1 2374:1 2370:0 2358:0 2355:S 2349:, 2346:0 2343:S 2335:1 2331:0 2323:2 2320:S 2314:1 2311:S 2305:0 2302:S 2297:Q 2254:2 2251:S 2248:( 2246:1 2242:→ 2237:2 2234:S 2224:1 2221:S 2218:( 2216:0 2212:→ 2207:2 2204:S 2194:0 2191:S 2188:( 2186:1 2182:→ 2177:1 2174:S 2164:2 2161:S 2158:( 2156:0 2152:→ 2147:1 2144:S 2134:1 2131:S 2128:( 2126:1 2122:→ 2117:0 2114:S 2104:0 2101:S 2098:( 2096:0 2092:→ 2087:0 2084:S 2070:→ 2065:0 2062:S 2046:2 2043:S 2040:( 2038:1 2034:→ 2029:1 2027:( 2024:2 2021:S 2011:1 2008:S 2005:( 2003:0 1999:→ 1994:0 1992:( 1989:2 1986:S 1976:0 1973:S 1970:( 1968:1 1964:→ 1959:1 1957:( 1954:1 1951:S 1941:2 1938:S 1935:( 1933:0 1929:→ 1924:0 1922:( 1919:1 1916:S 1906:1 1903:S 1900:( 1898:1 1894:→ 1889:1 1887:( 1884:0 1881:S 1871:0 1868:S 1865:( 1863:0 1859:→ 1854:0 1852:( 1849:0 1846:S 1832:→ 1829:) 1823:( 1820:0 1817:S 1802:2 1799:S 1793:) 1791:1 1789:, 1786:2 1783:S 1773:1 1770:S 1764:) 1762:0 1760:, 1757:2 1754:S 1744:0 1741:S 1735:) 1733:1 1731:, 1728:1 1725:S 1715:2 1712:S 1706:) 1704:0 1702:, 1699:1 1696:S 1686:1 1683:S 1677:) 1675:1 1673:, 1670:0 1667:S 1657:0 1654:S 1648:) 1646:0 1644:, 1641:0 1638:S 1617:2 1614:S 1610:1 1606:→ 1601:2 1598:S 1589:1 1586:S 1582:0 1578:→ 1573:2 1570:S 1561:0 1558:S 1554:1 1550:→ 1545:1 1542:S 1533:2 1530:S 1526:0 1522:→ 1517:1 1514:S 1505:1 1502:S 1498:1 1494:→ 1489:0 1486:S 1477:0 1474:S 1470:0 1466:→ 1461:0 1458:S 1448:→ 1443:0 1440:S 1290:, 1284:( 1258:( 1244:( 1211:( 1091:( 1051:( 1037:( 989:( 948:( 934:( 885:( 777:2 774:x 770:1 767:x 757:2 754:x 752:, 750:1 747:x 745:( 726:2 722:1 714:( 706:→ 701:2 691:1 683:( 670:) 664:( 656:→ 641:) 635:( 627:→ 612:) 606:( 598:→ 572:f 568:Q 560:, 552:Q 546:f 542:Q 538:F 534:Q 520:, 514:, 508:, 500:F 496:Q 492:F 451:( 432:i 428:x 423:Q 418:i 414:q 410:q 406:F 402:f 397:n 392:n 388:x 386:( 383:n 379:q 375:1 372:x 370:( 368:1 365:q 363:( 361:f 356:n 352:x 348:1 345:x 343:( 341:f 339:( 337:q 331:f 327:Q 321:Q 316:i 312:Q 306:i 302:Q 298:F 294:Q 290:F 277:f 273:Q 268:Q 264:F 256:f 254:( 252:q 248:f 244:f 242:( 240:q 236:f 232:f 228:n 219:i 215:x 210:Q 205:i 201:q 197:q 193:F 189:f 184:n 179:n 175:x 171:1 168:x 166:( 164:f 162:( 160:q 155:n 151:x 149:( 146:n 142:q 138:1 135:x 133:( 131:1 128:q 126:( 124:f 115:Q 110:f 106:Q 93:F 89:Q 84:f 80:Q 76:F 72:Q 68:F 20:.

Index

tree walking automaton
state machine
tree structures
strings
regular languages of trees
deterministic automaton
ranked alphabet
arity
transition rules
ground term
Infinite-tree automata
S2S
monadic second-order
Regular tree grammar#Examples
String
grammar

String
automaton

Tree
grammar


Deterministic finite (string) automaton
Deterministic finite automaton#Formal definition
(right) regular (string) grammar
regular tree grammar
equivalence relation
Myhill–Nerode theorem
Courcelle's theorem
Tree transducers
word transducers
word automata
Alternating tree automata
Infinite-tree automata

Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.