| i ≤ i0 + 1 ⊦ countFun(i, i0 + 1, intfun) = countFun(i, i0, intfun) + intfun(i0 + 1) ' |
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) '
Used simplifier rules: <; (wellfounded) Used terms: i→n(i0 - i)