Reserved Notation "a ~~> b" (at level 70, right associativity).
Reserved Notation "F ~~~> G" (at level 70, right associativity).
Reserved Notation "F <~~~> G" (at level 70, right associativity).
Reserved Notation "a ~~> b" (at level 70, right associativity).
Reserved Notation "F ~~~> G" (at level 70, right associativity).
Reserved Notation "F <~~~> G" (at level 70, right associativity).