A =:= A for all A (equality is reflexive). This also provides implicit views A <:< B when A <: B, because (A =:= A) <: (A <:< A) <: (A <:< B).
A =:= A for all A (equality is reflexive). This also provides implicit views A <:< B when A <: B, because (A =:= A) <: (A <:< A) <: (A <:< B).