module languages/sdf2/idioms/FirstLayout

exports

sorts ABC

lexical syntax
  [\ \t\n] -> LAYOUT
 
context-free start-symbols
  ABC

context-free syntax
  "a" "b"? "c" -> ABC

%% without the restriction, the term:
%% a c
%% is ambiguous because the space can be attributed
%% in between "a" and "b"?, or in between "b"? and "c"

context-free restrictions
  LAYOUT? -/- [\ \t\n]
