Metamath Proof Explorer


Theorem abvtrivg

Description: The trivial absolute value. This theorem is not true for rings with zero divisors, which violate the multiplication axiom; abvdom is the converse of this theorem. (Contributed by SN, 25-Jun-2025)

Ref Expression
Hypotheses abvtriv.a
|- A = ( AbsVal ` R )
abvtriv.b
|- B = ( Base ` R )
abvtriv.z
|- .0. = ( 0g ` R )
abvtriv.f
|- F = ( x e. B |-> if ( x = .0. , 0 , 1 ) )
Assertion abvtrivg
|- ( R e. Domn -> F e. A )

Proof

Step Hyp Ref Expression
1 abvtriv.a
 |-  A = ( AbsVal ` R )
2 abvtriv.b
 |-  B = ( Base ` R )
3 abvtriv.z
 |-  .0. = ( 0g ` R )
4 abvtriv.f
 |-  F = ( x e. B |-> if ( x = .0. , 0 , 1 ) )
5 eqid
 |-  ( .r ` R ) = ( .r ` R )
6 domnring
 |-  ( R e. Domn -> R e. Ring )
7 2 5 3 domnmuln0
 |-  ( ( R e. Domn /\ ( y e. B /\ y =/= .0. ) /\ ( z e. B /\ z =/= .0. ) ) -> ( y ( .r ` R ) z ) =/= .0. )
8 1 2 3 4 5 6 7 abvtrivd
 |-  ( R e. Domn -> F e. A )