Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - start with the Axiom of Extensionality
The difference, union, and intersection of two classes
The intersection of two classes
ineq1d
Next ⟩
ineq2d
Metamath Proof Explorer
Ascii
Unicode
Theorem
ineq1d
Description:
Equality deduction for intersection of two classes.
(Contributed by
NM
, 10-Apr-1994)
Ref
Expression
Hypothesis
ineq1d.1
⊢
φ
→
A
=
B
Assertion
ineq1d
⊢
φ
→
A
∩
C
=
B
∩
C
Proof
Step
Hyp
Ref
Expression
1
ineq1d.1
⊢
φ
→
A
=
B
2
ineq1
⊢
A
=
B
→
A
∩
C
=
B
∩
C
3
1
2
syl
⊢
φ
→
A
∩
C
=
B
∩
C