function [f, logscale] = fwd(engine, fpast, ev, t)% Forwards pass.bnet = bnet_from_engine(engine);ss = bnet.nnodes_per_slice;ev2 = cell(ss, 2);ev2(:,1) = fpast.evidence;ev2(:,2) = ev;CPDpot = cell(1,ss);for n=1:ss  fam = family(bnet.dag, n, 2);  e = bnet.equiv_class(n, 2);  CPDpot{n} = convert_to_pot(bnet.CPD{e}, engine.pot_type, fam(:), ev2);end       f.evidence = ev;f.t = t;% get priorint = engine.interface;if fpast.t==1  prior = marginalize_pot(fpast.clpot{engine.int_clq1}, int, engine.maximize);else  prior = marginalize_pot(fpast.clpot{engine.out_clq}, int+ss, engine.maximize);  prior = set_domain_pot(prior, int); % shift back to slice 1endpots = [ {prior} CPDpot ];slice1 = 1:ss;slice2 = slice1 + ss; CPDclqs = engine.clq_ass_to_node(slice2);D = engine.in_clq;clqs = [D CPDclqs];[f.clpot, f.seppot] =  init_pot(engine.jtree_engine, clqs, pots, engine.pot_type, engine.observed);[f.clpot, f.seppot] = collect_evidence(engine.jtree_engine, f.clpot, f.seppot);for c=1:length(f.clpot)  [f.clpot{c}, ll(c)] = normalize_pot(f.clpot{c});endlogscale = ll(engine.root);