Metamath Proof Explorer


Definition df-1r

Description: Define signed real constant 1. This is a "temporary" set used in the construction of complex numbers df-c , and is intended to be used only by the construction. From Proposition 9-4.2 of Gleason p. 126. (Contributed by NM, 9-Aug-1995) (New usage is discouraged.)

Ref Expression
Assertion df-1r 1 𝑹 = 1 𝑷 + 𝑷 1 𝑷 1 𝑷 ~ 𝑹

Detailed syntax breakdown

Step Hyp Ref Expression
0 c1r class 1 𝑹
1 c1p class 1 𝑷
2 cpp class + 𝑷
3 1 1 2 co class 1 𝑷 + 𝑷 1 𝑷
4 3 1 cop class 1 𝑷 + 𝑷 1 𝑷 1 𝑷
5 cer class ~ 𝑹
6 4 5 cec class 1 𝑷 + 𝑷 1 𝑷 1 𝑷 ~ 𝑹
7 0 6 wceq wff 1 𝑹 = 1 𝑷 + 𝑷 1 𝑷 1 𝑷 ~ 𝑹