trace_input?

persistent(a)?
persistent(b)?
persistent(c)?
persistent(d)?
persistent(e)?
persistent(f)?



check :-
	write("
a=",a,"
b=",b,"
c=",c,"
d=",d,"
e=",e,"
f=",f,"
").



a <<- billy_the_hilly(hair => knots,
			arms => long,
			teeth => yellow,
			eyes => red,
			voice => cracked,
			nails => {black;broken},
			nose => pimples,
			breath => bad,
			vehicle => truck(paint => gone,
					 gun_rack => full,
					 fuel_consumption => enormous,
					 size => much_too_big,
					 speed => really_slow,
					 location => in_front_of_you),
			feet => smelly,
			armpits => worse,
			belly => hangs_out,
			fingers => gnarled,
			mouth => full_of_beer,
			hand => down_his_pants) ?


a = @(feet => S), write(S),nl ?

a = @(hair => H, arms => A, teeth => T), write(H,A,T),nl ?

a = @(hair => H, arms => A, joke => bad, teeth => T) ?

a = @(hair => H, arms => A, aardvark => bad, teeth => T) ?

a = @(hair => H, arms => A, zebra => bad, teeth => T) ?

a <<- p(b,c), check?


b <<- 5, check ?

c <<- letters(a,b,c), check ?

a <<- q(a,b,c), check?

d <<- exam(b,a,c), check ?

e = a, check ?

d = exam(A,B,C), write(A,B,C), check ?
