constructor <;> try constructor <;> try constructor
a : String
⊢ Ø ⋁ ¬ₛ O↗ =ₛ O
case a
a : String
⊢ Sinf_const.eval (Sinf_const.coerce (O↗) (NoVars.S NoVars.O)) ≠ Sinf_const.eval (Sinf_const.coerce O NoVars.O)