Metamath Proof Explorer


Theorem absfun

Description: The absolute value is a function. (Contributed by Glauco Siliprandi, 11-Oct-2020)

Ref Expression
Assertion absfun
|- Fun abs

Proof

Step Hyp Ref Expression
1 absf
 |-  abs : CC --> RR
2 ffun
 |-  ( abs : CC --> RR -> Fun abs )
3 1 2 ax-mp
 |-  Fun abs