clpz:monotonic.

space(' ')   --> " ".
opCol([C|S]) --> [C], { member(C,"+*") }, sequence(space,"",S).
parse_line(Line,Parsed)  :- phrase(sequence(seq," ",Parsed),Line).
parse_spaces_number(S,N) :- phrase((sequence(space,"", _),number(N),sequence(space,"",_)),S).

input(Ops,Cols) :- phrase_from_file((sequence(seq,"\n",Lines),"\n",sequence(opCol," ",OpCols)),"i/06.in"),
	maplist(nth0(0),OpCols,Ops), maplist(maplist(same_length,OpCols),LinesOfNums),
	maplist(parse_line,Lines,LinesOfNums), transpose(LinesOfNums,Cols).

do_op('+')         --> sum.
do_op('*',Xs,Prod) :- foldl(\X^Y^Z^(#Z #= #X * #Y),Xs,1,Prod).

part(Ops)    --> maplist(maplist(parse_spaces_number)), maplist(do_op,Ops), sum.
solve(P1,P2) :- input(Ops,Cols), maplist(transpose,Cols,ColsT), part(Ops,Cols,P1), part(Ops,ColsT,P2).
test         :- make_test(day(6),solve,6891729672676,9770311947567).

Another fairly easy day. I'm especially happy with the maplist(maplist(same_length, OpCols), LineNums), which lines up all the columns for me. Also, there is secret tacit programming in Prolog with (-->)/2 !! So excited to have figured that out.

~/aoc25pl/06