| i ≤ i2 + 1, i1 + i = i2 + 1, 0 ≤ i2, i ≤ i2, 0 ≤ i, 0 ≤ i1, ∀ j0, i0, intfun. i→n(j0 - i0) < i→n(i1) → true → i0 ≤ j0 ∧ 0 ≤ i0 → countFun(i0, j0, intfun) = countFun(i0, j0 - 1, intfun) + intfun(j0) ' ⊦ intfun(i) ' + countFun(i + 1, i2 + 1, intfun) = countFun(i, i2, intfun) + intfun(i2 + 1) ' |
⊦ i ≤ j → countFun(i, j, intfun) = intfun(i) ' + countFun(i + 1, j, intfun)
i ≤ i2, i ≤ i2 + 1, i1 + i = i2 + 1, 0 ≤ i2, i ≤ i2, 0 ≤ i, 0 ≤ i1, ∀ j0, i0, intfun. i→n(j0 - i0) < i→n(i1) → true → i0 ≤ j0 ∧ 0 ≤ i0 → countFun(i0, j0, intfun) = countFun(i0, j0 - 1, intfun) + intfun(j0) ' ⊦ intfun(i) ' + countFun(i + 1, i2 + 1, intfun) = (intfun(i) ' + countFun(i + 1, i2, intfun)) + intfun(i2 + 1) '
Used terms: intfun, i2, i