| ⊦ gcd(i, j) = 1, 1 < gcd(i, j), ∃ i0. 1 < i0 ∧ i0 | i ∧ i0 | j |
⊦ ∃ i. 1 < i
Used simplifier rules: gcd-less-eq-zero: ⊦ gcd(i, j) ≤ 0 ↔ gcd(i, j) = 0;%gcd-zero-zero: ⊦ gcd(i, j) = 0 ↔ i = 0 ∧ j = 0;%gcd-zero: ⊦ gcd(0, 0) = 0;%div-zero-01: ⊦ i | 0;% ⊦ i < j ↔ ¬ j ≤ i; (ss)% ⊦ i < 1 ↔ i ≤ 0; (s)% ⊦ ¬ i < j → (i = j ↔ ¬ j < i); (ss)