Transformation of Applicative Specifications into Imperative ...

APPENDIX C. FORMAL SPECIFICATIONS OF TRANSFORMATIONS
end,
end
typings, func, trans, env, types),
(b3, env ′′ , types ′′ ) =
CheckValueExpr(
ve, Known(type_expr(res)), typings,
func, trans, env, types ′ ) in
b1 ∧ b2 ∧ b3 ∧
CheckTypeExpr(arg, typings, func, trans) ∧
CheckTypeExpr(
type_expr(res), typings, func, trans)
end
/∗Checks for transformability of a pre condition.
∗/
/∗
Arguments:
=======
precond: the pre condition
et: the expected type of the value expression
Results:
=====
Bool: true if the precondition is transformable,
false otherwise
∗/
CheckOptPreCondition :
OptionalPreCondition × ExpType × TYPINGS ×
FUNC × TRANS × ENV × TYPES →
Bool × ENV × TYPES
CheckOptPreCondition(
precond, et, typings, func, trans, env, types) ≡
case precond of
PreCondition(ve) →
let
(b, env ′ , types ′ ) =
CheckValueExpr(
ve, et, typings, func, trans, env, types)
in
(b ∧ CheckPreCondGen(ve, func, trans, types),
env ′ , types ′ )
end,
NoPreCondition → (true, env, types)
end,
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