Metamath Proof Explorer


Theorem jm2.27dlem5

Description: Lemma for rmydioph . Used with sselii to infer membership of midpoints of range; jm2.27dlem2 is deprecated. (Contributed by Stefan O'Rear, 11-Oct-2014)

Ref Expression
Hypotheses jm2.27dlem5.2 𝐵 = ( 𝐴 + 1 )
jm2.27dlem5.3 ( 1 ... 𝐵 ) ⊆ ( 1 ... 𝐶 )
Assertion jm2.27dlem5 ( 1 ... 𝐴 ) ⊆ ( 1 ... 𝐶 )

Proof

Step Hyp Ref Expression
1 jm2.27dlem5.2 𝐵 = ( 𝐴 + 1 )
2 jm2.27dlem5.3 ( 1 ... 𝐵 ) ⊆ ( 1 ... 𝐶 )
3 fzssp1 ( 1 ... 𝐴 ) ⊆ ( 1 ... ( 𝐴 + 1 ) )
4 1 oveq2i ( 1 ... 𝐵 ) = ( 1 ... ( 𝐴 + 1 ) )
5 3 4 sseqtrri ( 1 ... 𝐴 ) ⊆ ( 1 ... 𝐵 )
6 5 2 sstri ( 1 ... 𝐴 ) ⊆ ( 1 ... 𝐶 )