beta(Prot,Pos) :-pref(Prot,Pos,Pref),
Pref>0.8,
coil(Prot,Pos+4),
setof(X,beta40(Prot,Pos,X),S),
size(S,Sz),
Sz>=4.
There is a beta-strand at
position Pos in Protein Prot if there is a preference for betas at Pos
of at least 0.8 and there is a coil at Pos+4 and there are at least 4 pieces
of beta-strand within 40 positions of Pos.