Theorem intersection_neutr

Theorem. intersection_neutr
A ∩ UnivCl = A
Proof
01. 1 ⊢ x ∈ A ∩ UnivCl, hypo.
02. 1 ⊢ x ∈ A, intersection_eliml 1.
03. ⊢ x ∈ A ∩ UnivCl → x ∈ A, subj_intro 2.
04. 4 ⊢ x ∈ A, hypo.
05. 4 ⊢ set x, set_intro 4.
06. 4 ⊢ x ∈ UnivCl, UnivCl_intro 5.
07. 4 ⊢ x ∈ A ∩ UnivCl, intersection_intro 4 6.
08. ⊢ x ∈ A → x ∈ A ∩ UnivCl, subj_intro 7.
09. ⊢ x ∈ A ∩ UnivCl ↔ x ∈ A, bij_intro 3 8.
10. ⊢ ∀x. x ∈ A ∩ UnivCl ↔ x ∈ A, uq_intro 9.
intersection_neutr. ⊢ A ∩ UnivCl = A, ext 10.

Dependencies
The given proof depends on four axioms:
comp, eq_refl, eq_subst, ext.