Metamath Proof Explorer


Theorem absmulrposd

Description: Specialization of absmuld with absidd . (Contributed by Stanislas Polu, 9-Mar-2020)

Ref Expression
Hypotheses absmulrposd.1
|- ( ph -> 0 <_ A )
absmulrposd.2
|- ( ph -> A e. RR )
absmulrposd.3
|- ( ph -> B e. RR )
Assertion absmulrposd
|- ( ph -> ( abs ` ( A x. B ) ) = ( A x. ( abs ` B ) ) )

Proof

Step Hyp Ref Expression
1 absmulrposd.1
 |-  ( ph -> 0 <_ A )
2 absmulrposd.2
 |-  ( ph -> A e. RR )
3 absmulrposd.3
 |-  ( ph -> B e. RR )
4 2 recnd
 |-  ( ph -> A e. CC )
5 3 recnd
 |-  ( ph -> B e. CC )
6 4 5 absmuld
 |-  ( ph -> ( abs ` ( A x. B ) ) = ( ( abs ` A ) x. ( abs ` B ) ) )
7 2 1 absidd
 |-  ( ph -> ( abs ` A ) = A )
8 7 oveq1d
 |-  ( ph -> ( ( abs ` A ) x. ( abs ` B ) ) = ( A x. ( abs ` B ) ) )
9 6 8 eqtrd
 |-  ( ph -> ( abs ` ( A x. B ) ) = ( A x. ( abs ` B ) ) )