Metamath Proof Explorer


Theorem slelss

Description: If two surreals A and B share a birthday, then A <_s B if and only if the left set of A is a non-strict subset of the left set of B . (Contributed by Scott Fenton, 21-Mar-2025)

Ref Expression
Assertion slelss ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( 𝐴 ≤s 𝐵 ↔ ( L ‘ 𝐴 ) ⊆ ( L ‘ 𝐵 ) ) )

Proof

Step Hyp Ref Expression
1 sltlpss ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( 𝐴 <s 𝐵 ↔ ( L ‘ 𝐴 ) ⊊ ( L ‘ 𝐵 ) ) )
2 fveq2 ( 𝐴 = 𝐵 → ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) )
3 simpr ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) )
4 lruneq ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( ( L ‘ 𝐴 ) ∪ ( R ‘ 𝐴 ) ) = ( ( L ‘ 𝐵 ) ∪ ( R ‘ 𝐵 ) ) )
5 4 adantr ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( L ‘ 𝐴 ) ∪ ( R ‘ 𝐴 ) ) = ( ( L ‘ 𝐵 ) ∪ ( R ‘ 𝐵 ) ) )
6 5 3 difeq12d ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( ( L ‘ 𝐴 ) ∪ ( R ‘ 𝐴 ) ) ∖ ( L ‘ 𝐴 ) ) = ( ( ( L ‘ 𝐵 ) ∪ ( R ‘ 𝐵 ) ) ∖ ( L ‘ 𝐵 ) ) )
7 difundir ( ( ( L ‘ 𝐴 ) ∪ ( R ‘ 𝐴 ) ) ∖ ( L ‘ 𝐴 ) ) = ( ( ( L ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) ∪ ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) )
8 difid ( ( L ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) = ∅
9 8 uneq1i ( ( ( L ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) ∪ ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) ) = ( ∅ ∪ ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) )
10 0un ( ∅ ∪ ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) ) = ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) )
11 7 9 10 3eqtri ( ( ( L ‘ 𝐴 ) ∪ ( R ‘ 𝐴 ) ) ∖ ( L ‘ 𝐴 ) ) = ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) )
12 incom ( ( L ‘ 𝐴 ) ∩ ( R ‘ 𝐴 ) ) = ( ( R ‘ 𝐴 ) ∩ ( L ‘ 𝐴 ) )
13 lltropt ( L ‘ 𝐴 ) <<s ( R ‘ 𝐴 )
14 ssltdisj ( ( L ‘ 𝐴 ) <<s ( R ‘ 𝐴 ) → ( ( L ‘ 𝐴 ) ∩ ( R ‘ 𝐴 ) ) = ∅ )
15 13 14 mp1i ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( L ‘ 𝐴 ) ∩ ( R ‘ 𝐴 ) ) = ∅ )
16 12 15 eqtr3id ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( R ‘ 𝐴 ) ∩ ( L ‘ 𝐴 ) ) = ∅ )
17 disjdif2 ( ( ( R ‘ 𝐴 ) ∩ ( L ‘ 𝐴 ) ) = ∅ → ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) = ( R ‘ 𝐴 ) )
18 16 17 syl ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( R ‘ 𝐴 ) ∖ ( L ‘ 𝐴 ) ) = ( R ‘ 𝐴 ) )
19 11 18 eqtrid ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( ( L ‘ 𝐴 ) ∪ ( R ‘ 𝐴 ) ) ∖ ( L ‘ 𝐴 ) ) = ( R ‘ 𝐴 ) )
20 difundir ( ( ( L ‘ 𝐵 ) ∪ ( R ‘ 𝐵 ) ) ∖ ( L ‘ 𝐵 ) ) = ( ( ( L ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) ∪ ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) )
21 difid ( ( L ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) = ∅
22 21 uneq1i ( ( ( L ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) ∪ ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) ) = ( ∅ ∪ ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) )
23 0un ( ∅ ∪ ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) ) = ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) )
24 20 22 23 3eqtri ( ( ( L ‘ 𝐵 ) ∪ ( R ‘ 𝐵 ) ) ∖ ( L ‘ 𝐵 ) ) = ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) )
25 incom ( ( L ‘ 𝐵 ) ∩ ( R ‘ 𝐵 ) ) = ( ( R ‘ 𝐵 ) ∩ ( L ‘ 𝐵 ) )
26 lltropt ( L ‘ 𝐵 ) <<s ( R ‘ 𝐵 )
27 ssltdisj ( ( L ‘ 𝐵 ) <<s ( R ‘ 𝐵 ) → ( ( L ‘ 𝐵 ) ∩ ( R ‘ 𝐵 ) ) = ∅ )
28 26 27 mp1i ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( L ‘ 𝐵 ) ∩ ( R ‘ 𝐵 ) ) = ∅ )
29 25 28 eqtr3id ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( R ‘ 𝐵 ) ∩ ( L ‘ 𝐵 ) ) = ∅ )
30 disjdif2 ( ( ( R ‘ 𝐵 ) ∩ ( L ‘ 𝐵 ) ) = ∅ → ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) = ( R ‘ 𝐵 ) )
31 29 30 syl ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( R ‘ 𝐵 ) ∖ ( L ‘ 𝐵 ) ) = ( R ‘ 𝐵 ) )
32 24 31 eqtrid ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( ( L ‘ 𝐵 ) ∪ ( R ‘ 𝐵 ) ) ∖ ( L ‘ 𝐵 ) ) = ( R ‘ 𝐵 ) )
33 6 19 32 3eqtr3d ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( R ‘ 𝐴 ) = ( R ‘ 𝐵 ) )
34 3 33 oveq12d ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( L ‘ 𝐴 ) |s ( R ‘ 𝐴 ) ) = ( ( L ‘ 𝐵 ) |s ( R ‘ 𝐵 ) ) )
35 simpl1 ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → 𝐴 No )
36 lrcut ( 𝐴 No → ( ( L ‘ 𝐴 ) |s ( R ‘ 𝐴 ) ) = 𝐴 )
37 35 36 syl ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( L ‘ 𝐴 ) |s ( R ‘ 𝐴 ) ) = 𝐴 )
38 simpl2 ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → 𝐵 No )
39 lrcut ( 𝐵 No → ( ( L ‘ 𝐵 ) |s ( R ‘ 𝐵 ) ) = 𝐵 )
40 38 39 syl ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → ( ( L ‘ 𝐵 ) |s ( R ‘ 𝐵 ) ) = 𝐵 )
41 34 37 40 3eqtr3d ( ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) ∧ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) → 𝐴 = 𝐵 )
42 41 ex ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) → 𝐴 = 𝐵 ) )
43 2 42 impbid2 ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( 𝐴 = 𝐵 ↔ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) )
44 1 43 orbi12d ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( ( 𝐴 <s 𝐵𝐴 = 𝐵 ) ↔ ( ( L ‘ 𝐴 ) ⊊ ( L ‘ 𝐵 ) ∨ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) ) )
45 sleloe ( ( 𝐴 No 𝐵 No ) → ( 𝐴 ≤s 𝐵 ↔ ( 𝐴 <s 𝐵𝐴 = 𝐵 ) ) )
46 45 3adant3 ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( 𝐴 ≤s 𝐵 ↔ ( 𝐴 <s 𝐵𝐴 = 𝐵 ) ) )
47 sspss ( ( L ‘ 𝐴 ) ⊆ ( L ‘ 𝐵 ) ↔ ( ( L ‘ 𝐴 ) ⊊ ( L ‘ 𝐵 ) ∨ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) )
48 47 a1i ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( ( L ‘ 𝐴 ) ⊆ ( L ‘ 𝐵 ) ↔ ( ( L ‘ 𝐴 ) ⊊ ( L ‘ 𝐵 ) ∨ ( L ‘ 𝐴 ) = ( L ‘ 𝐵 ) ) ) )
49 44 46 48 3bitr4d ( ( 𝐴 No 𝐵 No ∧ ( bday 𝐴 ) = ( bday 𝐵 ) ) → ( 𝐴 ≤s 𝐵 ↔ ( L ‘ 𝐴 ) ⊆ ( L ‘ 𝐵 ) ) )