Module EnvSA.
Existing Instance Join_env.
Existing Instance Perm_env.
Existing Instance Sep_env.
Existing Instance Sing_env.
Existing Instance Canc_env.
Existing Instance Disj_env.
Existing Instance Cross_env.
Hint Resolve @empty_env_unit @empty_env_unit' : core.

Lemma env_join_sub1 {key: Type}{A: Type}:
forall rho1 rho2: env key A, (forall id x, env_get rho1 id = Some x -> env_get rho2 id = Some x) ->
join_sub rho1 rho2.