int_ne.fzn 243 Bytes
% RUNS ON flatzinc
% RUNS ON fzn_fd_canon
% RUNS ON fzn_fdlp_canon
% RUNS ON fzn_lazyfd_canon

var 0..2: x1 :: output_var;
var 2..4: x2 :: output_var;
constraint int_ne(3, 4);
constraint int_ne(1, 0);
constraint int_ne(x1, x2);
solve satisfy;