MAYBE proof of input_W5sNeyp3FW.trs # AProVE Commit ID: aff8ecad908e01718a4c36e68d2e55d5e0f16e15 fuhs 20220216 unpublished The Runtime Complexity (parallel-innermost) of the given CpxTRS could be proven to be BOUNDS(1, INF). (0) CpxTRS (1) RenamingProof [BOTH BOUNDS(ID, ID), 0 ms] (2) CpxTRS (3) CpxTrsToCdtProof [BOTH BOUNDS(ID, ID), 0 ms] (4) CdtProblem (5) CdtToCpxRelTrsProof [BOTH BOUNDS(ID, ID), 0 ms] (6) CpxRelTRS (7) RenamingProof [BOTH BOUNDS(ID, ID), 0 ms] (8) CpxRelTRS (9) TypeInferenceProof [BOTH BOUNDS(ID, ID), 0 ms] (10) typed CpxTrs (11) OrderProof [LOWER BOUND(ID), 9 ms] (12) typed CpxTrs (13) RelTrsToDecreasingLoopProblemProof [LOWER BOUND(ID), 0 ms] (14) TRS for Loop Detection (15) RelTrsToTrsProof [UPPER BOUND(ID), 0 ms] (16) CpxTRS (17) CpxTrsToCdtProof [UPPER BOUND(ID), 0 ms] (18) CdtProblem (19) CdtLeafRemovalProof [BOTH BOUNDS(ID, ID), 0 ms] (20) CdtProblem (21) CdtUsableRulesProof [BOTH BOUNDS(ID, ID), 0 ms] (22) CdtProblem (23) CdtToCpxRelTrsProof [BOTH BOUNDS(ID, ID), 0 ms] (24) CpxTRS (25) RelTrsToTrsProof [UPPER BOUND(ID), 0 ms] (26) CpxTRS (27) RelTrsToWeightedTrsProof [BOTH BOUNDS(ID, ID), 0 ms] (28) CpxWeightedTrs (29) TypeInferenceProof [BOTH BOUNDS(ID, ID), 0 ms] (30) CpxTypedWeightedTrs (31) CompletionProof [UPPER BOUND(ID), 0 ms] (32) CpxTypedWeightedCompleteTrs (33) NarrowingProof [BOTH BOUNDS(ID, ID), 0 ms] (34) CpxTypedWeightedCompleteTrs (35) CpxTypedWeightedTrsToRntsProof [UPPER BOUND(ID), 0 ms] (36) CpxRNTS (37) SimplificationProof [BOTH BOUNDS(ID, ID), 0 ms] (38) CpxRNTS (39) CpxRntsAnalysisOrderProof [BOTH BOUNDS(ID, ID), 0 ms] (40) CpxRNTS (41) ResultPropagationProof [UPPER BOUND(ID), 0 ms] (42) CpxRNTS (43) IntTrsBoundProof [UPPER BOUND(ID), 180 ms] (44) CpxRNTS (45) IntTrsBoundProof [UPPER BOUND(ID), 44 ms] (46) CpxRNTS (47) CompletionProof [UPPER BOUND(ID), 0 ms] (48) CpxTypedWeightedCompleteTrs (49) CpxTypedWeightedTrsToRntsProof [UPPER BOUND(ID), 0 ms] (50) CpxRNTS (51) RelTrsToWeightedTrsProof [UPPER BOUND(ID), 0 ms] (52) CpxWeightedTrs (53) TypeInferenceProof [BOTH BOUNDS(ID, ID), 0 ms] (54) CpxTypedWeightedTrs (55) CompletionProof [UPPER BOUND(ID), 0 ms] (56) CpxTypedWeightedCompleteTrs (57) NarrowingProof [BOTH BOUNDS(ID, ID), 0 ms] (58) CpxTypedWeightedCompleteTrs (59) CpxTypedWeightedTrsToRntsProof [UPPER BOUND(ID), 0 ms] (60) CpxRNTS (61) SimplificationProof [BOTH BOUNDS(ID, ID), 0 ms] (62) CpxRNTS (63) CpxRntsAnalysisOrderProof [BOTH BOUNDS(ID, ID), 0 ms] (64) CpxRNTS (65) ResultPropagationProof [UPPER BOUND(ID), 0 ms] (66) CpxRNTS (67) IntTrsBoundProof [UPPER BOUND(ID), 164 ms] (68) CpxRNTS (69) IntTrsBoundProof [UPPER BOUND(ID), 16 ms] (70) CpxRNTS (71) CompletionProof [UPPER BOUND(ID), 0 ms] (72) CpxTypedWeightedCompleteTrs (73) CpxTypedWeightedTrsToRntsProof [UPPER BOUND(ID), 0 ms] (74) CpxRNTS ---------------------------------------- (0) Obligation: The Runtime Complexity (parallel-innermost) of the given CpxTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: zeros -> cons(0, zeros) tail(cons(X, XS)) -> XS S is empty. Rewrite Strategy: PARALLEL_INNERMOST ---------------------------------------- (1) RenamingProof (BOTH BOUNDS(ID, ID)) Renamed function symbols to avoid clashes with predefined symbol. ---------------------------------------- (2) Obligation: The Runtime Complexity (parallel-innermost) of the given CpxTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: zeros -> cons(0', zeros) tail(cons(X, XS)) -> XS S is empty. Rewrite Strategy: PARALLEL_INNERMOST ---------------------------------------- (3) CpxTrsToCdtProof (BOTH BOUNDS(ID, ID)) Converted Cpx (relative) TRS with rewrite strategy PARALLEL_INNERMOST to CDT ---------------------------------------- (4) Obligation: Complexity Dependency Tuples Problem Rules: zeros -> cons(0, zeros) tail(cons(z0, z1)) -> z1 Tuples: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 S tuples: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 K tuples:none Defined Rule Symbols: zeros, tail_1 Defined Pair Symbols: ZEROS, TAIL_1 Compound Symbols: c_1, c1 ---------------------------------------- (5) CdtToCpxRelTrsProof (BOTH BOUNDS(ID, ID)) Converted S to standard rules, and D \ S as well as R to relative rules. ---------------------------------------- (6) Obligation: The Runtime Complexity (innermost) of the given CpxRelTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 The (relative) TRS S consists of the following rules: zeros -> cons(0, zeros) tail(cons(z0, z1)) -> z1 Rewrite Strategy: INNERMOST ---------------------------------------- (7) RenamingProof (BOTH BOUNDS(ID, ID)) Renamed function symbols to avoid clashes with predefined symbol. ---------------------------------------- (8) Obligation: The Runtime Complexity (innermost) of the given CpxRelTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 The (relative) TRS S consists of the following rules: zeros -> cons(0', zeros) tail(cons(z0, z1)) -> z1 Rewrite Strategy: INNERMOST ---------------------------------------- (9) TypeInferenceProof (BOTH BOUNDS(ID, ID)) Inferred types. ---------------------------------------- (10) Obligation: Innermost TRS: Rules: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 zeros -> cons(0', zeros) tail(cons(z0, z1)) -> z1 Types: ZEROS :: c c :: c -> c TAIL :: cons -> c1 cons :: 0' -> cons -> cons c1 :: c1 zeros :: cons 0' :: 0' tail :: cons -> cons hole_c1_2 :: c hole_c12_2 :: c1 hole_cons3_2 :: cons hole_0'4_2 :: 0' gen_c5_2 :: Nat -> c gen_cons6_2 :: Nat -> cons ---------------------------------------- (11) OrderProof (LOWER BOUND(ID)) Heuristically decided to analyse the following defined symbols: ZEROS, zeros ---------------------------------------- (12) Obligation: Innermost TRS: Rules: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 zeros -> cons(0', zeros) tail(cons(z0, z1)) -> z1 Types: ZEROS :: c c :: c -> c TAIL :: cons -> c1 cons :: 0' -> cons -> cons c1 :: c1 zeros :: cons 0' :: 0' tail :: cons -> cons hole_c1_2 :: c hole_c12_2 :: c1 hole_cons3_2 :: cons hole_0'4_2 :: 0' gen_c5_2 :: Nat -> c gen_cons6_2 :: Nat -> cons Generator Equations: gen_c5_2(0) <=> hole_c1_2 gen_c5_2(+(x, 1)) <=> c(gen_c5_2(x)) gen_cons6_2(0) <=> hole_cons3_2 gen_cons6_2(+(x, 1)) <=> cons(0', gen_cons6_2(x)) The following defined symbols remain to be analysed: ZEROS, zeros ---------------------------------------- (13) RelTrsToDecreasingLoopProblemProof (LOWER BOUND(ID)) Transformed a relative TRS into a decreasing-loop problem. ---------------------------------------- (14) Obligation: Analyzing the following TRS for decreasing loops: The Runtime Complexity (innermost) of the given CpxRelTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 The (relative) TRS S consists of the following rules: zeros -> cons(0, zeros) tail(cons(z0, z1)) -> z1 Rewrite Strategy: INNERMOST ---------------------------------------- (15) RelTrsToTrsProof (UPPER BOUND(ID)) transformed relative TRS to TRS ---------------------------------------- (16) Obligation: The Runtime Complexity (parallel-innermost) of the given CpxTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: zeros -> cons(0, zeros) tail(cons(X, XS)) -> XS S is empty. Rewrite Strategy: PARALLEL_INNERMOST ---------------------------------------- (17) CpxTrsToCdtProof (UPPER BOUND(ID)) Converted Cpx (relative) TRS with rewrite strategy PARALLEL_INNERMOST to CDT ---------------------------------------- (18) Obligation: Complexity Dependency Tuples Problem Rules: zeros -> cons(0, zeros) tail(cons(z0, z1)) -> z1 Tuples: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 S tuples: ZEROS -> c(ZEROS) TAIL(cons(z0, z1)) -> c1 K tuples:none Defined Rule Symbols: zeros, tail_1 Defined Pair Symbols: ZEROS, TAIL_1 Compound Symbols: c_1, c1 ---------------------------------------- (19) CdtLeafRemovalProof (BOTH BOUNDS(ID, ID)) Removed 1 trailing nodes: TAIL(cons(z0, z1)) -> c1 ---------------------------------------- (20) Obligation: Complexity Dependency Tuples Problem Rules: zeros -> cons(0, zeros) tail(cons(z0, z1)) -> z1 Tuples: ZEROS -> c(ZEROS) S tuples: ZEROS -> c(ZEROS) K tuples:none Defined Rule Symbols: zeros, tail_1 Defined Pair Symbols: ZEROS Compound Symbols: c_1 ---------------------------------------- (21) CdtUsableRulesProof (BOTH BOUNDS(ID, ID)) The following rules are not usable and were removed: zeros -> cons(0, zeros) tail(cons(z0, z1)) -> z1 ---------------------------------------- (22) Obligation: Complexity Dependency Tuples Problem Rules:none Tuples: ZEROS -> c(ZEROS) S tuples: ZEROS -> c(ZEROS) K tuples:none Defined Rule Symbols:none Defined Pair Symbols: ZEROS Compound Symbols: c_1 ---------------------------------------- (23) CdtToCpxRelTrsProof (BOTH BOUNDS(ID, ID)) Converted S to standard rules, and D \ S as well as R to relative rules. ---------------------------------------- (24) Obligation: The Runtime Complexity (innermost) of the given CpxTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: ZEROS -> c(ZEROS) S is empty. Rewrite Strategy: INNERMOST ---------------------------------------- (25) RelTrsToTrsProof (UPPER BOUND(ID)) transformed relative TRS to TRS ---------------------------------------- (26) Obligation: The Runtime Complexity (innermost) of the given CpxTRS could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: ZEROS -> c(ZEROS) S is empty. Rewrite Strategy: INNERMOST ---------------------------------------- (27) RelTrsToWeightedTrsProof (BOTH BOUNDS(ID, ID)) Transformed relative TRS to weighted TRS ---------------------------------------- (28) Obligation: The Runtime Complexity (innermost) of the given CpxWeightedTrs could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: ZEROS -> c(ZEROS) [1] Rewrite Strategy: INNERMOST ---------------------------------------- (29) TypeInferenceProof (BOTH BOUNDS(ID, ID)) Infered types. ---------------------------------------- (30) Obligation: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: ZEROS -> c(ZEROS) [1] The TRS has the following type information: ZEROS :: c c :: c -> c Rewrite Strategy: INNERMOST ---------------------------------------- (31) CompletionProof (UPPER BOUND(ID)) The transformation into a RNTS is sound, since: (a) The obligation is a constructor system where every type has a constant constructor, (b) The following defined symbols do not have to be completely defined, as they can never occur inside other defined symbols: ZEROS (c) The following functions are completely defined: none Due to the following rules being added: none And the following fresh constants: const ---------------------------------------- (32) Obligation: Runtime Complexity Weighted TRS where critical functions are completely defined. The underlying TRS is: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: ZEROS -> c(ZEROS) [1] The TRS has the following type information: ZEROS :: c c :: c -> c const :: c Rewrite Strategy: INNERMOST ---------------------------------------- (33) NarrowingProof (BOTH BOUNDS(ID, ID)) Narrowed the inner basic terms of all right-hand sides by a single narrowing step. ---------------------------------------- (34) Obligation: Runtime Complexity Weighted TRS where critical functions are completely defined. The underlying TRS is: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: ZEROS -> c(ZEROS) [1] The TRS has the following type information: ZEROS :: c c :: c -> c const :: c Rewrite Strategy: INNERMOST ---------------------------------------- (35) CpxTypedWeightedTrsToRntsProof (UPPER BOUND(ID)) Transformed the TRS into an over-approximating RNTS by (improved) Size Abstraction. The constant constructors are abstracted as follows: const => 0 ---------------------------------------- (36) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: ---------------------------------------- (37) SimplificationProof (BOTH BOUNDS(ID, ID)) Simplified the RNTS by moving equalities from the constraints into the right-hand sides. ---------------------------------------- (38) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: ---------------------------------------- (39) CpxRntsAnalysisOrderProof (BOTH BOUNDS(ID, ID)) Found the following analysis order by SCC decomposition: { ZEROS } ---------------------------------------- (40) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: Function symbols to be analyzed: {ZEROS} ---------------------------------------- (41) ResultPropagationProof (UPPER BOUND(ID)) Applied inner abstraction using the recently inferred runtime/size bounds where possible. ---------------------------------------- (42) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: Function symbols to be analyzed: {ZEROS} ---------------------------------------- (43) IntTrsBoundProof (UPPER BOUND(ID)) Computed SIZE bound using CoFloCo for: ZEROS after applying outer abstraction to obtain an ITS, resulting in: O(1) with polynomial bound: 0 ---------------------------------------- (44) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: Function symbols to be analyzed: {ZEROS} Previous analysis results are: ZEROS: runtime: ?, size: O(1) [0] ---------------------------------------- (45) IntTrsBoundProof (UPPER BOUND(ID)) Computed RUNTIME bound using CoFloCo for: ZEROS after applying outer abstraction to obtain an ITS, resulting in: INF with polynomial bound: ? ---------------------------------------- (46) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: Function symbols to be analyzed: {ZEROS} Previous analysis results are: ZEROS: runtime: INF, size: O(1) [0] ---------------------------------------- (47) CompletionProof (UPPER BOUND(ID)) The TRS is a completely defined constructor system, as every type has a constant constructor and the following rules were added: none And the following fresh constants: const ---------------------------------------- (48) Obligation: Runtime Complexity Weighted TRS where all functions are completely defined. The underlying TRS is: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: ZEROS -> c(ZEROS) [1] The TRS has the following type information: ZEROS :: c c :: c -> c const :: c Rewrite Strategy: INNERMOST ---------------------------------------- (49) CpxTypedWeightedTrsToRntsProof (UPPER BOUND(ID)) Transformed the TRS into an over-approximating RNTS by (improved) Size Abstraction. The constant constructors are abstracted as follows: const => 0 ---------------------------------------- (50) Obligation: Complexity RNTS consisting of the following rules: ZEROS -{ 1 }-> 1 + ZEROS :|: Only complete derivations are relevant for the runtime complexity. ---------------------------------------- (51) RelTrsToWeightedTrsProof (UPPER BOUND(ID)) Transformed relative TRS to weighted TRS ---------------------------------------- (52) Obligation: The Runtime Complexity (innermost) of the given CpxWeightedTrs could be proven to be BOUNDS(1, INF). The TRS R consists of the following rules: zeros -> cons(0, zeros) [1] tail(cons(X, XS)) -> XS [1] Rewrite Strategy: INNERMOST ---------------------------------------- (53) TypeInferenceProof (BOTH BOUNDS(ID, ID)) Infered types. ---------------------------------------- (54) Obligation: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: zeros -> cons(0, zeros) [1] tail(cons(X, XS)) -> XS [1] The TRS has the following type information: zeros :: cons cons :: 0 -> cons -> cons 0 :: 0 tail :: cons -> cons Rewrite Strategy: INNERMOST ---------------------------------------- (55) CompletionProof (UPPER BOUND(ID)) The transformation into a RNTS is sound, since: (a) The obligation is a constructor system where every type has a constant constructor, (b) The following defined symbols do not have to be completely defined, as they can never occur inside other defined symbols: zeros tail_1 (c) The following functions are completely defined: none Due to the following rules being added: none And the following fresh constants: const ---------------------------------------- (56) Obligation: Runtime Complexity Weighted TRS where critical functions are completely defined. The underlying TRS is: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: zeros -> cons(0, zeros) [1] tail(cons(X, XS)) -> XS [1] The TRS has the following type information: zeros :: cons cons :: 0 -> cons -> cons 0 :: 0 tail :: cons -> cons const :: cons Rewrite Strategy: INNERMOST ---------------------------------------- (57) NarrowingProof (BOTH BOUNDS(ID, ID)) Narrowed the inner basic terms of all right-hand sides by a single narrowing step. ---------------------------------------- (58) Obligation: Runtime Complexity Weighted TRS where critical functions are completely defined. The underlying TRS is: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: zeros -> cons(0, zeros) [1] tail(cons(X, XS)) -> XS [1] The TRS has the following type information: zeros :: cons cons :: 0 -> cons -> cons 0 :: 0 tail :: cons -> cons const :: cons Rewrite Strategy: INNERMOST ---------------------------------------- (59) CpxTypedWeightedTrsToRntsProof (UPPER BOUND(ID)) Transformed the TRS into an over-approximating RNTS by (improved) Size Abstraction. The constant constructors are abstracted as follows: 0 => 0 const => 0 ---------------------------------------- (60) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 zeros -{ 1 }-> 1 + 0 + zeros :|: ---------------------------------------- (61) SimplificationProof (BOTH BOUNDS(ID, ID)) Simplified the RNTS by moving equalities from the constraints into the right-hand sides. ---------------------------------------- (62) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 zeros -{ 1 }-> 1 + 0 + zeros :|: ---------------------------------------- (63) CpxRntsAnalysisOrderProof (BOTH BOUNDS(ID, ID)) Found the following analysis order by SCC decomposition: { zeros } { tail } ---------------------------------------- (64) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 zeros -{ 1 }-> 1 + 0 + zeros :|: Function symbols to be analyzed: {zeros}, {tail} ---------------------------------------- (65) ResultPropagationProof (UPPER BOUND(ID)) Applied inner abstraction using the recently inferred runtime/size bounds where possible. ---------------------------------------- (66) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 zeros -{ 1 }-> 1 + 0 + zeros :|: Function symbols to be analyzed: {zeros}, {tail} ---------------------------------------- (67) IntTrsBoundProof (UPPER BOUND(ID)) Computed SIZE bound using CoFloCo for: zeros after applying outer abstraction to obtain an ITS, resulting in: O(1) with polynomial bound: 0 ---------------------------------------- (68) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 zeros -{ 1 }-> 1 + 0 + zeros :|: Function symbols to be analyzed: {zeros}, {tail} Previous analysis results are: zeros: runtime: ?, size: O(1) [0] ---------------------------------------- (69) IntTrsBoundProof (UPPER BOUND(ID)) Computed RUNTIME bound using CoFloCo for: zeros after applying outer abstraction to obtain an ITS, resulting in: INF with polynomial bound: ? ---------------------------------------- (70) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 zeros -{ 1 }-> 1 + 0 + zeros :|: Function symbols to be analyzed: {zeros}, {tail} Previous analysis results are: zeros: runtime: INF, size: O(1) [0] ---------------------------------------- (71) CompletionProof (UPPER BOUND(ID)) The TRS is a completely defined constructor system, as every type has a constant constructor and the following rules were added: tail(v0) -> null_tail [0] And the following fresh constants: null_tail ---------------------------------------- (72) Obligation: Runtime Complexity Weighted TRS where all functions are completely defined. The underlying TRS is: Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: zeros -> cons(0, zeros) [1] tail(cons(X, XS)) -> XS [1] tail(v0) -> null_tail [0] The TRS has the following type information: zeros :: cons:null_tail cons :: 0 -> cons:null_tail -> cons:null_tail 0 :: 0 tail :: cons:null_tail -> cons:null_tail null_tail :: cons:null_tail Rewrite Strategy: INNERMOST ---------------------------------------- (73) CpxTypedWeightedTrsToRntsProof (UPPER BOUND(ID)) Transformed the TRS into an over-approximating RNTS by (improved) Size Abstraction. The constant constructors are abstracted as follows: 0 => 0 null_tail => 0 ---------------------------------------- (74) Obligation: Complexity RNTS consisting of the following rules: tail(z) -{ 1 }-> XS :|: z = 1 + X + XS, X >= 0, XS >= 0 tail(z) -{ 0 }-> 0 :|: v0 >= 0, z = v0 zeros -{ 1 }-> 1 + 0 + zeros :|: Only complete derivations are relevant for the runtime complexity.