Metamath Proof Explorer


Theorem dford3lem1

Description: Lemma for dford3 . (Contributed by Stefan O'Rear, 28-Oct-2014)

Ref Expression
Assertion dford3lem1 ( ( Tr 𝑁 ∧ ∀ 𝑦𝑁 Tr 𝑦 ) → ∀ 𝑏𝑁 ( Tr 𝑏 ∧ ∀ 𝑦𝑏 Tr 𝑦 ) )

Proof

Step Hyp Ref Expression
1 treq ( 𝑦 = 𝑏 → ( Tr 𝑦 ↔ Tr 𝑏 ) )
2 1 cbvralvw ( ∀ 𝑦𝑁 Tr 𝑦 ↔ ∀ 𝑏𝑁 Tr 𝑏 )
3 2 biimpi ( ∀ 𝑦𝑁 Tr 𝑦 → ∀ 𝑏𝑁 Tr 𝑏 )
4 3 adantl ( ( Tr 𝑁 ∧ ∀ 𝑦𝑁 Tr 𝑦 ) → ∀ 𝑏𝑁 Tr 𝑏 )
5 trss ( Tr 𝑁 → ( 𝑏𝑁𝑏𝑁 ) )
6 ssralv ( 𝑏𝑁 → ( ∀ 𝑦𝑁 Tr 𝑦 → ∀ 𝑦𝑏 Tr 𝑦 ) )
7 5 6 syl6 ( Tr 𝑁 → ( 𝑏𝑁 → ( ∀ 𝑦𝑁 Tr 𝑦 → ∀ 𝑦𝑏 Tr 𝑦 ) ) )
8 7 com23 ( Tr 𝑁 → ( ∀ 𝑦𝑁 Tr 𝑦 → ( 𝑏𝑁 → ∀ 𝑦𝑏 Tr 𝑦 ) ) )
9 8 imp ( ( Tr 𝑁 ∧ ∀ 𝑦𝑁 Tr 𝑦 ) → ( 𝑏𝑁 → ∀ 𝑦𝑏 Tr 𝑦 ) )
10 9 ralrimiv ( ( Tr 𝑁 ∧ ∀ 𝑦𝑁 Tr 𝑦 ) → ∀ 𝑏𝑁𝑦𝑏 Tr 𝑦 )
11 r19.26 ( ∀ 𝑏𝑁 ( Tr 𝑏 ∧ ∀ 𝑦𝑏 Tr 𝑦 ) ↔ ( ∀ 𝑏𝑁 Tr 𝑏 ∧ ∀ 𝑏𝑁𝑦𝑏 Tr 𝑦 ) )
12 4 10 11 sylanbrc ( ( Tr 𝑁 ∧ ∀ 𝑦𝑁 Tr 𝑦 ) → ∀ 𝑏𝑁 ( Tr 𝑏 ∧ ∀ 𝑦𝑏 Tr 𝑦 ) )