assignment7 tweaks

[lambda.git] / hints / assignment_7_hint_6.mdwn

diff --git a/hints/assignment_7_hint_6.mdwn b/hints/assignment_7_hint_6.mdwn
index 344451a..740eba2 100644 (file)
--- a/hints/assignment_7_hint_6.mdwn
+++ b/hints/assignment_7_hint_6.mdwn
@@ -8,12 +8,14 @@
        Here's how to do that in our framework:
 
                type clause_op = bool dpm -> bool dpm set;;
+               
+               (* filter out which bool dpms in a set are true when receiving (r, h) as input *)
+               let extensions set (r, h) = List.filter (fun one_dpm -> let (truth_value, _, _) = one_dpm (r, h) in truth_value) set;;
 
                let negate_op (phi : clause_op) : clause_op =
                        fun one_dpm -> unit_set (
                 fun (r, h) ->
-                    let extensions set = List.filter (fun one_dpm -> let (truth_value, _, _) = one_dpm (r, h) in truth_value) set
-                                       in let truth_value' = extensions (phi one_dpm) = []
+                                       let truth_value' = extensions (phi one_dpm) (r, h) = []
                     in (truth_value', r, h)
             )
 
@@ -29,16 +31,17 @@
                        (* NOT: negate_op (and_op (negate_op phi) (negate_op psi)) *)
             fun one_dpm -> unit_set (
                 fun (r, h) ->
-                    let extensions set = List.filter (fun one_dpm -> let (truth_value, _, _) = one_dpm (r, h) in truth_value) set
-                                       in let truth_value' = extensions (phi one_dpm) <> [] || extensions (bind_set (negate_op phi one_dpm) psi) <> []
+                                       in let truth_value' = extensions (phi one_dpm) (r, h) <> [] || extensions (bind_set (negate_op phi one_dpm) psi) (r, h) <> []
                     in (truth_value', r, h))
 
                let if_op (phi : clause_op) (psi : clause_op) : clause_op =
                        (* NOT: negate_op (and_op phi (negate_op psi)) *)
             fun one_dpm -> unit_set (
               fun (r, h) ->
-                    let extensions set = List.filter (fun one_dpm -> let (truth_value, _, _) = one_dpm (r, h) in truth_value) set
-                                       in let truth_value' = List.for_all (fun one_dpm -> let (truth_value, _, _) = one_dpm (r, h) in truth_value = false || extensions (psi one_dpm) <> []) (phi one_dpm)
+                                       in let truth_value' = List.for_all (fun one_dpm ->
+                                                       let (truth_value, _, _) = one_dpm (r, h)
+                                                       in truth_value = false || extensions (psi one_dpm) (r, h) <> []
+                                               ) (phi one_dpm)
                     in (truth_value', r, h));;