SetOption lean::parser::verbose false. Notation 10 if _ then _ : implies. print Environment 1. print if true then false. Variable a : Bool. print if true then if a then false. SetOption lean::pp::notation false. print if true then if a then false. Variable A : Type. Variable f : A -> A -> A -> Bool. Notation 100 _ |- _ ; _ : f. print Environment 1. Variable c : A. Variable d : A. Variable e : A. print c |- d ; e. SetOption lean::pp::notation true. print c |- d ; e. Variable fact : A -> A. Notation 20 _ ! : fact. print c! !. SetOption lean::pp::notation false. print c! !. SetOption lean::pp::notation true. Variable g : A -> A -> A. Notation 30 [ _ ; _ ] : g print [c;d]. print [c ; [d;e] ]. SetOption lean::pp::notation false. print [c ; [d;e] ]. SetOption lean::pp::notation true. Variable h : A -> A -> A. Notation 40 _ << _ end : h. print Environment 1. print d << e end. print [c ; d << e end ]. SetOption lean::pp::notation false. print [c ; d << e end ]. SetOption lean::pp::notation true. Variable r : A -> A -> A. Infixl 30 ++ : r. Variable s : A -> A -> A. Infixl 40 ** : s. print c ** d ++ e ** c. Variable p1 : Bool. Variable p2 : Bool. Variable p3 : Bool. print p1 || p2 && p3. SetOption lean::pp::notation false. print c ** d ++ e ** c. print p1 || p2 && p3. SetOption lean::pp::notation true. print c = d || d = c. print not p1 || p2. print p1 && p3 || p2 && p3. SetOption lean::pp::notation false. print not p1 || p2. print p1 && p3 || p2 && p3.