propositional/syntax/modules.elf

%read "base.elf".

%sig Truth = {
  %include Base   %open o.
  true  : o.
}.

%sig Falsity = {
  %include Base   %open o.
  false : o.
}.

%sig NEG = {
  %include Base   %open o.
  not   : o -> o.           %prefix 20 not.
}.

%sig IMP = {
  %include Base   %open o.
  imp   : o -> o -> o.      %infix right 5 imp.
}.

%sig CONJ = {
  %include Base   %open o.
  and   : o -> o -> o.      %infix left 10 and.
}.

%sig DISJ = {
  %include Base   %open o.
  or   : o -> o -> o.       %infix left 10 or.
}.