Metamath Proof Explorer


Theorem rrx2pnedifcoorneorr

Description: If two different points X and Y in a real Euclidean space of dimension 2 are different, then at least one difference of two corresponding coordinates is not 0. (Contributed by AV, 26-Feb-2023)

Ref Expression
Hypotheses rrx2pnecoorneor.i
|- I = { 1 , 2 }
rrx2pnecoorneor.b
|- P = ( RR ^m I )
rrx2pnedifcoorneor.a
|- A = ( ( Y ` 1 ) - ( X ` 1 ) )
rrx2pnedifcoorneorr.b
|- B = ( ( X ` 2 ) - ( Y ` 2 ) )
Assertion rrx2pnedifcoorneorr
|- ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( A =/= 0 \/ B =/= 0 ) )

Proof

Step Hyp Ref Expression
1 rrx2pnecoorneor.i
 |-  I = { 1 , 2 }
2 rrx2pnecoorneor.b
 |-  P = ( RR ^m I )
3 rrx2pnedifcoorneor.a
 |-  A = ( ( Y ` 1 ) - ( X ` 1 ) )
4 rrx2pnedifcoorneorr.b
 |-  B = ( ( X ` 2 ) - ( Y ` 2 ) )
5 eqid
 |-  ( ( Y ` 2 ) - ( X ` 2 ) ) = ( ( Y ` 2 ) - ( X ` 2 ) )
6 1 2 3 5 rrx2pnedifcoorneor
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( A =/= 0 \/ ( ( Y ` 2 ) - ( X ` 2 ) ) =/= 0 ) )
7 eqcom
 |-  ( ( Y ` 2 ) = ( X ` 2 ) <-> ( X ` 2 ) = ( Y ` 2 ) )
8 7 a1i
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( Y ` 2 ) = ( X ` 2 ) <-> ( X ` 2 ) = ( Y ` 2 ) ) )
9 1 2 rrx2pyel
 |-  ( X e. P -> ( X ` 2 ) e. RR )
10 9 recnd
 |-  ( X e. P -> ( X ` 2 ) e. CC )
11 1 2 rrx2pyel
 |-  ( Y e. P -> ( Y ` 2 ) e. RR )
12 11 recnd
 |-  ( Y e. P -> ( Y ` 2 ) e. CC )
13 10 12 anim12i
 |-  ( ( X e. P /\ Y e. P ) -> ( ( X ` 2 ) e. CC /\ ( Y ` 2 ) e. CC ) )
14 13 ancomd
 |-  ( ( X e. P /\ Y e. P ) -> ( ( Y ` 2 ) e. CC /\ ( X ` 2 ) e. CC ) )
15 14 3adant3
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( Y ` 2 ) e. CC /\ ( X ` 2 ) e. CC ) )
16 subeq0
 |-  ( ( ( Y ` 2 ) e. CC /\ ( X ` 2 ) e. CC ) -> ( ( ( Y ` 2 ) - ( X ` 2 ) ) = 0 <-> ( Y ` 2 ) = ( X ` 2 ) ) )
17 15 16 syl
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( ( Y ` 2 ) - ( X ` 2 ) ) = 0 <-> ( Y ` 2 ) = ( X ` 2 ) ) )
18 13 3adant3
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( X ` 2 ) e. CC /\ ( Y ` 2 ) e. CC ) )
19 subeq0
 |-  ( ( ( X ` 2 ) e. CC /\ ( Y ` 2 ) e. CC ) -> ( ( ( X ` 2 ) - ( Y ` 2 ) ) = 0 <-> ( X ` 2 ) = ( Y ` 2 ) ) )
20 18 19 syl
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( ( X ` 2 ) - ( Y ` 2 ) ) = 0 <-> ( X ` 2 ) = ( Y ` 2 ) ) )
21 8 17 20 3bitr4d
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( ( Y ` 2 ) - ( X ` 2 ) ) = 0 <-> ( ( X ` 2 ) - ( Y ` 2 ) ) = 0 ) )
22 4 eqcomi
 |-  ( ( X ` 2 ) - ( Y ` 2 ) ) = B
23 22 eqeq1i
 |-  ( ( ( X ` 2 ) - ( Y ` 2 ) ) = 0 <-> B = 0 )
24 21 23 bitrdi
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( ( Y ` 2 ) - ( X ` 2 ) ) = 0 <-> B = 0 ) )
25 24 necon3bid
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( ( Y ` 2 ) - ( X ` 2 ) ) =/= 0 <-> B =/= 0 ) )
26 25 orbi2d
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( ( A =/= 0 \/ ( ( Y ` 2 ) - ( X ` 2 ) ) =/= 0 ) <-> ( A =/= 0 \/ B =/= 0 ) ) )
27 6 26 mpbid
 |-  ( ( X e. P /\ Y e. P /\ X =/= Y ) -> ( A =/= 0 \/ B =/= 0 ) )