Metamath Proof Explorer


Theorem seq1p

Description: Removing the first term from a sequence. (Contributed by NM, 17-Mar-2005) (Revised by Mario Carneiro, 27-May-2014)

Ref Expression
Hypotheses seqsplit.1 φ x S y S x + ˙ y S
seqsplit.2 φ x S y S z S x + ˙ y + ˙ z = x + ˙ y + ˙ z
seqsplit.3 φ N M + 1
seq1p.4 φ M
seq1p.5 φ x M N F x S
Assertion seq1p φ seq M + ˙ F N = F M + ˙ seq M + 1 + ˙ F N

Proof

Step Hyp Ref Expression
1 seqsplit.1 φ x S y S x + ˙ y S
2 seqsplit.2 φ x S y S z S x + ˙ y + ˙ z = x + ˙ y + ˙ z
3 seqsplit.3 φ N M + 1
4 seq1p.4 φ M
5 seq1p.5 φ x M N F x S
6 uzid M M M
7 4 6 syl φ M M
8 1 2 3 7 5 seqsplit φ seq M + ˙ F N = seq M + ˙ F M + ˙ seq M + 1 + ˙ F N
9 seq1 M seq M + ˙ F M = F M
10 4 9 syl φ seq M + ˙ F M = F M
11 10 oveq1d φ seq M + ˙ F M + ˙ seq M + 1 + ˙ F N = F M + ˙ seq M + 1 + ˙ F N
12 8 11 eqtrd φ seq M + ˙ F N = F M + ˙ seq M + 1 + ˙ F N