Heuristic quantifier closing applied rule all left
And closed the goal!
Rule argument
pos: left 2 terms: a
Additional information
Used simplifier rules:
count-1: ⊦ count(a, ∅ ++ a) = 1; from specification bag-basic%not-zero: 0 < n ⊦ (* n) ≤ m → m ≠ 0; (forward) from specification nat
Used terms: a