Added in combinator reduction axioms for B' C' and S'. Also split the original reduction axioms into separate files: I+K, B+C, S, B'+C', S'.
%ID: $Id$
%Author: Jia Meng, NICTA
%const-typed combinator reduction for S
%S P Q R --> P R (Q R)
input_clause(a2,axiom,
[++equal(hAPP(hAPP(hAPP(c_COMBS(A,B,C),P),Q),R),hAPP(hAPP(P,R),hAPP(Q,R)))]).