| i ≤ i0 + 1, ∀ i1, i2, intfun. i→n(i1 - i2) < i→n(i0 - i) → i2 ≤ i1 + 1 → countFun(i2, i1 + 1, intfun) = countFun(i2, i1, intfun) + intfun(i1 + 1) ' ⊦ countFun(i, i0 + 1, intfun) = countFun(i, i0, intfun) + intfun(i0 + 1) ' |
i0 = i3 + i, i ≤ i0 + 1, ∀ i1, i2, intfun. i→n(i1 - i2) < i→n(i3) → i2 ≤ i1 + 1 → countFun(i2, i1 + 1, intfun) = countFun(i2, i1, intfun) + intfun(i1 + 1) ' ⊦ countFun(i, i0 + 1, intfun) = countFun(i, i0, intfun) + intfun(i0 + 1) '
Used simplifier rules: ⊦ i0 = i - j ↔ i = i0 + j; (elim) Used terms: i0, i, i3