Database
REAL AND COMPLEX NUMBERS
Order sets
Infinity and the extended real number system (cont.)
xaddid2
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xaddid1d
Metamath Proof Explorer
Ascii
Unicode
Theorem
xaddid2
Description:
Extended real version of
addid2
.
(Contributed by
Mario Carneiro
, 20-Aug-2015)
Ref
Expression
Assertion
xaddid2
⊢
A
∈
ℝ
*
→
0
+
𝑒
A
=
A
Proof
Step
Hyp
Ref
Expression
1
0xr
⊢
0
∈
ℝ
*
2
xaddcom
⊢
0
∈
ℝ
*
∧
A
∈
ℝ
*
→
0
+
𝑒
A
=
A
+
𝑒
0
3
1
2
mpan
⊢
A
∈
ℝ
*
→
0
+
𝑒
A
=
A
+
𝑒
0
4
xaddid1
⊢
A
∈
ℝ
*
→
A
+
𝑒
0
=
A
5
3
4
eqtrd
⊢
A
∈
ℝ
*
→
0
+
𝑒
A
=
A