inferred-effect word prop is just a boolean now, not an effect object

basis/stack-checker/backend/backend.factor

@@ -146,11 +146,10 @@ M: object apply-object push-literal ;
     [ 3drop ] [ effect-error ] if ;
 
 : finish-word ( word -- )
-    current-effect
-    [ check-effect ]
-    [ drop recorded get push ]
-    [ "inferred-effect" set-word-prop ]
-    2tri ;
+    [ current-effect check-effect ]
+    [ recorded get push ]
+    [ t "inferred-effect" set-word-prop ]
+    tri ;
 
 : cannot-infer-effect ( word -- * )
     "cannot-infer" word-prop throw ;

core/effects/effects.factor

@@ -44,9 +44,7 @@ M: effect effect>string ( effect -- string )
 
 GENERIC: stack-effect ( word -- effect/f )
 
-M: word stack-effect
-    { "declared-effect" "inferred-effect" }
-    swap props>> [ at ] curry map [ ] find nip ;
+M: word stack-effect "declared-effect" word-prop ;
 
 M: deferred stack-effect call-next-method (( -- * )) or ;