Section believe_monotonicity.
Context {CS: compspecs} {Espec: OracleKind}.
End believe_monotonicity.

Lemma semax__mono {CS} Espec Delta Delta'
(SUB: tycontext_sub Delta Delta') sem P c R:
derives (@semax_ Espec sem {| sa_cs := CS; sa_Delta := Delta; sa_P := P; sa_c := c; sa_R := R |})
(@semax_ Espec sem {| sa_cs:=CS; sa_Delta := Delta'; sa_P := P; sa_c := c; sa_R := R |}).