Database
REAL AND COMPLEX NUMBERS
Reflexive and transitive closures of relations
Definitions and basic properties of transitive closures
trcleq2lem
Next ⟩
cvbtrcl
Metamath Proof Explorer
Ascii
Unicode
Theorem
trcleq2lem
Description:
Equality implies bijection.
(Contributed by
RP
, 5-May-2020)
Ref
Expression
Assertion
trcleq2lem
⊢
A
=
B
→
R
⊆
A
∧
A
∘
A
⊆
A
↔
R
⊆
B
∧
B
∘
B
⊆
B
Proof
Step
Hyp
Ref
Expression
1
sseq2
⊢
A
=
B
→
R
⊆
A
↔
R
⊆
B
2
id
⊢
A
=
B
→
A
=
B
3
2
2
coeq12d
⊢
A
=
B
→
A
∘
A
=
B
∘
B
4
3
2
sseq12d
⊢
A
=
B
→
A
∘
A
⊆
A
↔
B
∘
B
⊆
B
5
1
4
anbi12d
⊢
A
=
B
→
R
⊆
A
∧
A
∘
A
⊆
A
↔
R
⊆
B
∧
B
∘
B
⊆
B