Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Infinity
Transitive closure of a relation
ttrcleq
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Ascii
Unicode
Theorem
ttrcleq
Description:
Equality theorem for transitive closure.
(Contributed by
Scott Fenton
, 17-Oct-2024)
Ref
Expression
Assertion
ttrcleq
⊢
R
=
S
→
t++
R
=
t++
S
Proof
Step
Hyp
Ref
Expression
1
breq
⊢
R
=
S
→
f
⁡
m
R
f
⁡
suc
⁡
m
↔
f
⁡
m
S
f
⁡
suc
⁡
m
2
1
ralbidv
⊢
R
=
S
→
∀
m
∈
n
f
⁡
m
R
f
⁡
suc
⁡
m
↔
∀
m
∈
n
f
⁡
m
S
f
⁡
suc
⁡
m
3
2
3anbi3d
⊢
R
=
S
→
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
R
f
⁡
suc
⁡
m
↔
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
S
f
⁡
suc
⁡
m
4
3
exbidv
⊢
R
=
S
→
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
R
f
⁡
suc
⁡
m
↔
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
S
f
⁡
suc
⁡
m
5
4
rexbidv
⊢
R
=
S
→
∃
n
∈
ω
∖
1
𝑜
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
R
f
⁡
suc
⁡
m
↔
∃
n
∈
ω
∖
1
𝑜
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
S
f
⁡
suc
⁡
m
6
5
opabbidv
⊢
R
=
S
→
x
y
|
∃
n
∈
ω
∖
1
𝑜
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
R
f
⁡
suc
⁡
m
=
x
y
|
∃
n
∈
ω
∖
1
𝑜
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
S
f
⁡
suc
⁡
m
7
df-ttrcl
⊢
t++
R
=
x
y
|
∃
n
∈
ω
∖
1
𝑜
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
R
f
⁡
suc
⁡
m
8
df-ttrcl
⊢
t++
S
=
x
y
|
∃
n
∈
ω
∖
1
𝑜
∃
f
f
Fn
suc
⁡
n
∧
f
⁡
∅
=
x
∧
f
⁡
n
=
y
∧
∀
m
∈
n
f
⁡
m
S
f
⁡
suc
⁡
m
9
6
7
8
3eqtr4g
⊢
R
=
S
→
t++
R
=
t++
S