keep(
[
[comment,1]
]
).

keep1(
[
%[comment,1],
%/*,
[writeln,1],
[write,1],
[cut,0],
[true,0],
[fail,0],
[false,0],
[halt,0],
[halt,1],
[trace,0],
[notrace,0],
[equals4_on,0],
[equals4_off,0],
[assertz,1],
[atomic,1],
[close,2],
[close,1],
[at_end_of_stream,0],
[at_end_of_stream,1],
[compound,1],
[float,1],
[set_prolog_flag,2],
[integer,1],
[set_input,1],
[set_output,1],
[nonvar,1],
[put_char,2],
[put_char,1],
[put_code,2],
[put_code,1],
[nl,0],
[nl,1],
[write,2],
[write,1],
[writeq,2],
[writeq,1]
%*/
]).