simp at hl
case right.intro.intro
hpo b c k : ℕplus
hk : ↑b = ↑hpo * ↑k
l : ℕplus
hl : ↑hpo = ↑{ val := ↑b * ↑l, property := (_ : ↑b * ↑l ≠ 0) }
⊢ hpo = b
case right.intro.intro
hpo b c k : ℕplus
hk : ↑b = ↑hpo * ↑k
l : ℕplus
hl : ↑hpo = ↑b * ↑l
⊢ hpo = b