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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