simp at hk
case right.intro.intro
hpo b c k : ℕplus
hk : ↑b = ↑hpo * 1
l : ℕplus
hl : ↑k = 1 ∧ ↑l = 1
⊢ ↑hpo = ↑b
case right.intro.intro
hpo b c k l : ℕplus
hl : ↑k = 1 ∧ ↑l = 1
hk : ↑b = ↑hpo
⊢ ↑hpo = ↑b