Metamath Proof Explorer


Theorem ltrelsr

Description: Signed real 'less than' is a relation on signed reals. (Contributed by NM, 14-Feb-1996) (New usage is discouraged.)

Ref Expression
Assertion ltrelsr <𝑹𝑹×𝑹

Proof

Step Hyp Ref Expression
1 df-ltr <𝑹=xy|x𝑹y𝑹zwvux=zw~𝑹y=vu~𝑹z+𝑷u<𝑷w+𝑷v
2 opabssxp xy|x𝑹y𝑹zwvux=zw~𝑹y=vu~𝑹z+𝑷u<𝑷w+𝑷v𝑹×𝑹
3 1 2 eqsstri <𝑹𝑹×𝑹