/**

Metaphysics > Walking Simulator

robotwalker.pl

From quote: speed, spacing of steps, how high the feet and knees are lifted up.


robotwalker(3,3,
[[1,3,d,b],[2,3,d,b],[3,3,d,b],
 [1,2,d,b],[2,2,d,b],[3,2,d,b]
 [1,1,d,b],[2,1,d,b],[3,1,d,b]],

%% call robot X,Y,InitialState,FinalState

state 0


state m
y 3 a a
y y1 :
	x 

	for x=1 to 3
		let d=y-x
		let m=mod(d/2)
		if m=m1 then f2 x y
	next x
next y
reset all to back

],

m 1
f2 x y
	u
	f
	d

to x y a b list1, ? list3
	list1=[x, y, a, C]
	append(list2,[[x,y,b,C]],list3)
	
to x y a b list1, ? list3
        list1=[x, y, C, a]
        append(list2,[[x,y,C,b]],list3)
	
to x y a b list1, list2, list3


reset all to back
        for x=1 to 3
		to x y f b
        next x
next y

%%**

%% X and Y are the number of legs across and along the robot, InitialState includes status (up or down, and forward or backward) of each leg, Program indicates the legs' statuses with time and Frames includes the frame number, position on path and status of each leg

robotwalker(X,Y,InitialState,Program,Frames) :-
	

compile1(Query,Functions,Result) :-
	compile2(Query,Functions,[],Result).
compile2(Query,Functions,Variables,Result) :-
	Query=[Query1|Queries]

**/

evaluate(matches(A,B)) :-
	A=B.
evaluate(A,A) :-
	number(A).
evaluate(A,A) :-
	atom(A).
evaluate(equals(A,B),A=D) :-
        evaluate(B,D).
evaluate(A+B,C) :-
        evaluate(A,D),
        evaluate(B,E),
        C is D+E.
evaluate(A-B,C) :-
	evaluate(A,D),
	evaluate(B,E),
	C is D-E.
evaluate(mod(A,B),C) :-
	C is mod(A,B).
evaluate(Function,Query,Functions,Variables,Result) :-
	Function = Head :- Body.

tokenise(File,Functions) :-
	open(File,read,Str),
	readfn([],Functions).
readfn(Functions1,Functions2) :-
	readfnhead(Head),
	get(':-'),
	readfnbody(Body).
readfnhead(Head) :-
	readfnname(Name),
	get('('),
	readfnargs(Arguments),
	get(')'),
readfnname(Name) :-
	getword(Name).
readfnargs(Arguments) :-
	
readfnbody(Body) :-
	getword(.

get(Char),