1 files changed, 68 insertions, 0 deletions
diff --git a/samples/Prolog/calc.pl b/samples/Prolog/calc.pl
new file mode 100644
index 0000000..b7492ca
--- /dev/null
+++ b/samples/Prolog/calc.pl
@@ -0,0 +1,68 @@
+action_module(calculator) .
+
+
+%[-,-,d1,-] --push(D)-->          [-,-,D,-]  if mode(init)
+push(D) < -
+  mode(init),
+  deny([displayed(D1),mode(init)]),
+  affirm([displayed(D),mode(cont)]).
+
+%[-,-,D1,-] --push(D)-->          [-,-,10*D1+D,-]  if mode(cont)
+push(D) < -
+  mode(cont),
+  deny(displayed(D1)),
+  New = 10*D1 + D,
+  affirm(displayed(New)).
+
+%[a,op,d,m] --push(clear)-->      [0,nop,0,0]
+push(clear) < -
+  deny([accumulator(A),op(O),displayed(D),memory(M),mode(X)]),
+  affirm([accumulator(0),op(nop),displayed(0),memory(0),mode(init)]).
+
+%[a,op,d,m] --push(mem_rec)-->    [a,op,m,m]
+push(mem_rec) < -
+  memory(M),
+  deny([displayed(D),mode(X)]),
+  affirm([displayed(M),mode(init)]).
+
+%[a,op,d,m] --push(plus)-->       [op(a,d),plus,d,m]
+push(plus) < -
+  displayed(D),
+  deny([accumulator(A),op(O),mode(X)]),
+  eval(O,A,D,V),   ; use normal arithmetic, i.e., V=O(A,D)
+  affirm([accumulator(V),op(plus),mode(init)]).
+
+%[a,op,d,m] --push(minus)-->      [op(a,d,minus,d,m]
+push(minus) lt -
+  displayed(D),
+  deny([accumulator(A),op(O),mode(X)]),
+  eval(O,A,D,V),   ; use normal arithmetic, i.e., V=O(A,D)
+  affirm([accumulator(V),op(minus),mode(init)]).
+
+%[a,op,d,m] --push(times)-->      [op(a,d),times,d,m]
+push(times) < -
+  displayed(D),
+  deny([accumulator(A),op(O),mode(X)]),
+  eval(O,A,D,V),   ; use normal arithmetic, i.e., V=O(A,D)
+  affirm([accumulator(V),op(times),mode(init)]).
+
+%[a,op,d,m] --push(equal)-->      [a,nop,op(a,d),m]
+push(equal) < -
+  accumulator(A),
+  deny([op(O),displayed(D),mode(X)]),
+  eval(O,A,D,V),
+  affirm([op(nop),displayed(V),mode(init)]).
+
+%[a,op,d,m] --push(mem_plus)-->   [a,nop,v,plus(m,v)] where v=op(a,d)
+push(mem_plus) < -
+  accumulator(A),
+  deny([op(O),displayed(D),memory(M),mode(X)]),
+  eval(O,A,D,V),
+  eval(plus,M,V,V1),
+  affirm([op(nop),displayed(V),memory(V1),mode(init)]).
+
+%[a,op,d,m] --push(plus_minus)--> [a,op,-d,m]
+push(clear) < -
+  deny([displayed(D),mode(X)]),
+  eval(minus,0,D,V),
+  affirm([displayed(V),mode(init)]).