Section WT_CONTEXT.
Variable cenv: composite_env.
Variable tenv: typenv.
Variable a a': expr.
Hypothesis SAMETY: typeof a' = typeof a.

(* Specifications: *)
Lemma wt_subexpr:
forall from to C,
context from to C ->
wt_expr_kind cenv tenv to (C a) ->
wt_expr_kind cenv tenv from a
with wt_subexprlist:
forall from C,
contextlist from C ->
wt_exprlist cenv tenv (C a) ->
wt_expr_kind cenv tenv from a.
Lemma typeof_context:
forall from to C, context from to C -> typeof (C a') = typeof (C a).
Lemma wt_arguments_context:
forall k C, contextlist k C ->
forall tyl, wt_arguments (C a) tyl -> wt_arguments (C a') tyl.
Lemma wt_context:
forall from to C,
context from to C ->
wt_expr_kind cenv tenv to (C a) ->
wt_expr_kind cenv tenv from a' ->
wt_expr_kind cenv tenv to (C a')
with wt_contextlist:
forall from C,
contextlist from C ->
wt_exprlist cenv tenv (C a) ->
wt_expr_kind cenv tenv from a' ->
wt_exprlist cenv tenv (C a').