Section CENV_SUB.
Context {CS CS': compspecs}
(CSUB: cenv_sub (@cenv_cs CS) (@cenv_cs CS')).
Definition is_tc_FF (a: tc_assert) :=
match a with tc_FF _ => True | _ => False end.
Definition dec_tc_FF (a: tc_assert) : {is_tc_FF a}+{~is_tc_FF a}.

Lemma tc_nonzero'_cenv_sub a rho w:
app_pred (@denote_tc_assert CS (@tc_nonzero' a) rho) w ->
app_pred (@denote_tc_assert CS' (@tc_nonzero' a) rho) w.