pfc_lambda([A1],Body,A1):-Body.
pfc_lambda([A1,A2],Body,A1,A2):-Body.
pfc_lambda([A1,A2,A3],Body,A1,A2,A3):-Body.
pfc_lambda([A1,A2,A3,A4],Body,A1,A2,A3,A4):-Body.


 ?-  maplist(pfc_lambda([X-Y],writeln(["I see ",X," and ",Y])),[a-b,c-d]).








C:\pf\swi666\bin>swipl
% c:/users/administrator/appdata/roaming/swi-prolog/pl.ini compiled 0.00 sec, 4 clauses
Welcome TO SWI-Prolog (Multi-threaded, 64 bits, Version 6.6.6)
Copyright (c) 1990-2013 University of Amsterdam, VU Amsterdam
SWI-Prolog comes with ABSOLUTELY NO WARRANTY. This is free software,
AND you are welcome TO redistribute it under certain conditions.
Please visit http://www.swi-prolog.org FOR details.

FOR help, use ?- help(Topic). OR ?- apropos(Word).

1 ?- asserta((pfc2_lambda(A,B,A):-B)).

true.

2 ?- maplist(pfc2_lambda(X,writeln(X)),[a,b]).
a
false.

3 ?- trace,maplist(pfc2_lambda(X,writeln(X)),[a,b]).
^  Call: (7) apply:maplist(pfc2_lambda(_G1936, writeln(_G1936)), [a, b]) ? creep
   Call: (8) apply:maplist_([a, b], user:pfc2_lambda(_G1936, writeln(_G1936))) ? creep
   Call: (9) pfc2_lambda(_G1936, writeln(_G1936), a) ? creep
   Call: (10) writeln(a) ? creep
a
   EXIT: (10) writeln(a) ? creep
   EXIT: (9) pfc2_lambda(a, writeln(a), a) ? creep
   Call: (9) apply:maplist_([b], user:pfc2_lambda(a, writeln(a))) ? creep
   Call: (10) pfc2_lambda(a, writeln(a), b) ? creep
   Fail: (10) pfc2_lambda(a, writeln(a), b) ? creep
   Fail: (9) apply:maplist_([b], user:pfc2_lambda(a, writeln(a))) ? creep
   Fail: (8) apply:maplist_([a, b], user:pfc2_lambda(_G1936, writeln(_G1936))) ? creep
^  Fail: (7) apply:maplist(user:pfc2_lambda(_G1936, writeln(_G1936)), [a, b]) ? creep
false.