Metamath Proof Explorer


Theorem ipiiie0

Description: The multiplicative inverse of _i (per i4 ) is also its additive inverse. (Contributed by SN, 30-Jun-2024)

Ref Expression
Assertion ipiiie0 ( i + ( i · ( i · i ) ) ) = 0

Proof

Step Hyp Ref Expression
1 it1ei ( i · 1 ) = i
2 1 eqcomi i = ( i · 1 )
3 reixi ( i · i ) = ( 0 − 1 )
4 3 oveq2i ( i · ( i · i ) ) = ( i · ( 0 − 1 ) )
5 2 4 oveq12i ( i + ( i · ( i · i ) ) ) = ( ( i · 1 ) + ( i · ( 0 − 1 ) ) )
6 ax-icn i ∈ ℂ
7 ax-1cn 1 ∈ ℂ
8 1re 1 ∈ ℝ
9 rernegcl ( 1 ∈ ℝ → ( 0 − 1 ) ∈ ℝ )
10 8 9 ax-mp ( 0 − 1 ) ∈ ℝ
11 10 recni ( 0 − 1 ) ∈ ℂ
12 6 7 11 adddii ( i · ( 1 + ( 0 − 1 ) ) ) = ( ( i · 1 ) + ( i · ( 0 − 1 ) ) )
13 renegid ( 1 ∈ ℝ → ( 1 + ( 0 − 1 ) ) = 0 )
14 8 13 ax-mp ( 1 + ( 0 − 1 ) ) = 0
15 14 oveq2i ( i · ( 1 + ( 0 − 1 ) ) ) = ( i · 0 )
16 sn-it0e0 ( i · 0 ) = 0
17 15 16 eqtri ( i · ( 1 + ( 0 − 1 ) ) ) = 0
18 5 12 17 3eqtr2i ( i + ( i · ( i · i ) ) ) = 0