Metamath Proof Explorer


Theorem m1p1sr

Description: Minus one plus one is zero for signed reals. (Contributed by NM, 5-May-1996) (New usage is discouraged.)

Ref Expression
Assertion m1p1sr -1𝑹+𝑹1𝑹=0𝑹

Proof

Step Hyp Ref Expression
1 df-m1r -1𝑹=1𝑷1𝑷+𝑷1𝑷~𝑹
2 df-1r 1𝑹=1𝑷+𝑷1𝑷1𝑷~𝑹
3 1 2 oveq12i -1𝑹+𝑹1𝑹=1𝑷1𝑷+𝑷1𝑷~𝑹+𝑹1𝑷+𝑷1𝑷1𝑷~𝑹
4 df-0r 0𝑹=1𝑷1𝑷~𝑹
5 1pr 1𝑷𝑷
6 addclpr 1𝑷𝑷1𝑷𝑷1𝑷+𝑷1𝑷𝑷
7 5 5 6 mp2an 1𝑷+𝑷1𝑷𝑷
8 addsrpr 1𝑷𝑷1𝑷+𝑷1𝑷𝑷1𝑷+𝑷1𝑷𝑷1𝑷𝑷1𝑷1𝑷+𝑷1𝑷~𝑹+𝑹1𝑷+𝑷1𝑷1𝑷~𝑹=1𝑷+𝑷1𝑷+𝑷1𝑷1𝑷+𝑷1𝑷+𝑷1𝑷~𝑹
9 5 7 7 5 8 mp4an 1𝑷1𝑷+𝑷1𝑷~𝑹+𝑹1𝑷+𝑷1𝑷1𝑷~𝑹=1𝑷+𝑷1𝑷+𝑷1𝑷1𝑷+𝑷1𝑷+𝑷1𝑷~𝑹
10 addasspr 1𝑷+𝑷1𝑷+𝑷1𝑷=1𝑷+𝑷1𝑷+𝑷1𝑷
11 10 oveq2i 1𝑷+𝑷1𝑷+𝑷1𝑷+𝑷1𝑷=1𝑷+𝑷1𝑷+𝑷1𝑷+𝑷1𝑷
12 addclpr 1𝑷𝑷1𝑷+𝑷1𝑷𝑷1𝑷+𝑷1𝑷+𝑷1𝑷𝑷
13 5 7 12 mp2an 1𝑷+𝑷1𝑷+𝑷1𝑷𝑷
14 addclpr 1𝑷+𝑷1𝑷𝑷1𝑷𝑷1𝑷+𝑷1𝑷+𝑷1𝑷𝑷
15 7 5 14 mp2an 1𝑷+𝑷1𝑷+𝑷1𝑷𝑷
16 enreceq 1𝑷𝑷1𝑷𝑷1𝑷+𝑷1𝑷+𝑷1𝑷𝑷1𝑷+𝑷1𝑷+𝑷1𝑷𝑷1𝑷1𝑷~𝑹=1𝑷+𝑷1𝑷+𝑷1𝑷1𝑷+𝑷1𝑷+𝑷1𝑷~𝑹1𝑷+𝑷1𝑷+𝑷1𝑷+𝑷1𝑷=1𝑷+𝑷1𝑷+𝑷1𝑷+𝑷1𝑷
17 5 5 13 15 16 mp4an 1𝑷1𝑷~𝑹=1𝑷+𝑷1𝑷+𝑷1𝑷1𝑷+𝑷1𝑷+𝑷1𝑷~𝑹1𝑷+𝑷1𝑷+𝑷1𝑷+𝑷1𝑷=1𝑷+𝑷1𝑷+𝑷1𝑷+𝑷1𝑷
18 11 17 mpbir 1𝑷1𝑷~𝑹=1𝑷+𝑷1𝑷+𝑷1𝑷1𝑷+𝑷1𝑷+𝑷1𝑷~𝑹
19 9 18 eqtr4i 1𝑷1𝑷+𝑷1𝑷~𝑹+𝑹1𝑷+𝑷1𝑷1𝑷~𝑹=1𝑷1𝑷~𝑹
20 4 19 eqtr4i 0𝑹=1𝑷1𝑷+𝑷1𝑷~𝑹+𝑹1𝑷+𝑷1𝑷1𝑷~𝑹
21 3 20 eqtr4i -1𝑹+𝑹1𝑹=0𝑹