macbroy30 is on 10.12 Sierra (already since 04-Mar-2017) -- discontinued support for 10.8 Mountain Lion;
(* Title: HOL/Library/Quotient_Syntax.thy
Author: Cezary Kaliszyk and Christian Urban
*)
section \<open>Pretty syntax for Quotient operations\<close>
theory Quotient_Syntax
imports Main
begin
notation
rel_conj (infixr "OOO" 75) and
map_fun (infixr "--->" 55) and
rel_fun (infixr "===>" 55)
end