⊦ i0 ∈ countFun(i, j, intfun) ↔ (∃ j0. i ≤ j0 ∧ j0 ≤ j ∧ intfun(j0) = i0)
i ≤ i0, i0 ≤ j, i ≤ j ⊦ ∃ j0. i ≤ j0 ∧ j0 ≤ j ∧ intfun(j0) = intfun(i0)
Used terms: intfun, j, i, intfun(i0)