[Imprint][Data Privacy Statement][E-Mail]

View long theorem info. View the proof. Back to main index. View the specification. View theorem base summary, View theorem base listing, the used properties by spec, the dependency list, the symbol table,

Proof step 52 from proof nextl-lemma-butlast-nonempty (previous step)

lf(m) = [], lf(0) = a ', m ≤ n0, ∀ n, a. nextl(n, a) ≠ [], m - 1 < n0 → lf((m - 1) + 1) = nextl(m - 1, lf(m - 1).last) ∧ lf(m - 1) ≠ [] ⊦ m = n0 + 1

User applied rule insert elim lemma

And obtained the following new goals

Proof step 53:
m = m0 + 1 ∧ m ≠ 0, lf(m) = [], lf(0) = a ', m ≤ n0, ∀ n, a. nextl(n, a) ≠ [], m0 < n0 → lf(m0 + 1) = nextl(m0, lf(m0).last) ∧ lf(m0) ≠ [] ⊦ m = n0 + 1

Rule argument

spec: nat inst: name: elim-pred-c seq: n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1 subst: [n, m] → [m, m0] flags: []

Additional information

Used simplifier rules: oz: ⊦ m + 1 ≠ 0; from specification nat-basic2%a: ⊦ (m + n0) + n1 = m + n0 + n1; from specification nat-basic2%c: ⊦ m + n = n + m; from specification nat-basic2%lez: ⊦ 0 ≤ m; from specification nat%e: ⊦ a ' ≠ []; from specification list%n ≠ 0 ⊦ m = n - 1 ↔ n = m + 1; (elim) Used terms: m, m0