apply BigStep.seq
case mpr
S : Stmt
s t : State
h : (S, s) ⟹ t
⊢ (S; Stmt.skip, s) ⟹ t
case mpr.hS
S : Stmt
s t : State
h : (S, s) ⟹ t
⊢ (S, s) ⟹ ?mpr.t

case mpr.hT
S : Stmt
s t : State
h : (S, s) ⟹ t
⊢ (Stmt.skip, ?mpr.t) ⟹ t

case mpr.t
S : Stmt
s t : State
h : (S, s) ⟹ t
⊢ State