Function prop::quality::sesh_in_left_arg

pub fn sesh_in_left_arg<A: Prop, B: Prop, C: Prop>(
    sesh_ab: Not<Q<A, B>>, 
    eq_ac: Eq<A, C>
) -> Not<Q<C, B>>

¬(a ~~ b) ⋀ (a == c) => ¬(c ~~ b).