Metamath Proof Explorer


Theorem oadif1lem

Description: Express the set difference of a continuous sum and its left addend as a class of sums. (Contributed by RP, 13-Feb-2025)

Ref Expression
Hypotheses oadif1lem.cl1 A On B On A ˙ B On
oadif1lem.cl2 A On b On A ˙ b On
oadif1lem.sub A On B On A y y A ˙ B b B A ˙ b = y
oadif1lem.ord A On B On b B A ˙ b A ˙ B
oadif1lem.word A On b On A A ˙ b
Assertion oadif1lem A On B On A ˙ B A = x | b B x = A ˙ b

Proof

Step Hyp Ref Expression
1 oadif1lem.cl1 A On B On A ˙ B On
2 oadif1lem.cl2 A On b On A ˙ b On
3 oadif1lem.sub A On B On A y y A ˙ B b B A ˙ b = y
4 oadif1lem.ord A On B On b B A ˙ b A ˙ B
5 oadif1lem.word A On b On A A ˙ b
6 simpl A On B On A On
7 onelon A ˙ B On y A ˙ B y On
8 1 7 sylan A On B On y A ˙ B y On
9 ontri1 A On y On A y ¬ y A
10 6 8 9 syl2an2r A On B On y A ˙ B A y ¬ y A
11 10 pm5.32da A On B On y A ˙ B A y y A ˙ B ¬ y A
12 ancom y A ˙ B A y A y y A ˙ B
13 11 12 bitr3di A On B On y A ˙ B ¬ y A A y y A ˙ B
14 13 3 sylbida A On B On y A ˙ B ¬ y A b B A ˙ b = y
15 eqcom A ˙ b = y y = A ˙ b
16 15 rexbii b B A ˙ b = y b B y = A ˙ b
17 14 16 sylib A On B On y A ˙ B ¬ y A b B y = A ˙ b
18 17 ex A On B On y A ˙ B ¬ y A b B y = A ˙ b
19 simpr A On B On b B y = A ˙ b y = A ˙ b
20 4 imp A On B On b B A ˙ b A ˙ B
21 20 adantr A On B On b B y = A ˙ b A ˙ b A ˙ B
22 19 21 eqeltrd A On B On b B y = A ˙ b y A ˙ B
23 simpr A On B On B On
24 onelon B On b B b On
25 23 24 sylan A On B On b B b On
26 6 25 5 syl2an2r A On B On b B A A ˙ b
27 6 25 2 syl2an2r A On B On b B A ˙ b On
28 ontri1 A On A ˙ b On A A ˙ b ¬ A ˙ b A
29 6 27 28 syl2an2r A On B On b B A A ˙ b ¬ A ˙ b A
30 26 29 mpbid A On B On b B ¬ A ˙ b A
31 30 adantr A On B On b B y = A ˙ b ¬ A ˙ b A
32 19 31 eqneltrd A On B On b B y = A ˙ b ¬ y A
33 22 32 jca A On B On b B y = A ˙ b y A ˙ B ¬ y A
34 33 rexlimdva2 A On B On b B y = A ˙ b y A ˙ B ¬ y A
35 18 34 impbid A On B On y A ˙ B ¬ y A b B y = A ˙ b
36 eldif y A ˙ B A y A ˙ B ¬ y A
37 vex y V
38 eqeq1 x = y x = A ˙ b y = A ˙ b
39 38 rexbidv x = y b B x = A ˙ b b B y = A ˙ b
40 37 39 elab y x | b B x = A ˙ b b B y = A ˙ b
41 35 36 40 3bitr4g A On B On y A ˙ B A y x | b B x = A ˙ b
42 41 eqrdv A On B On A ˙ B A = x | b B x = A ˙ b