Metamath Proof Explorer


Theorem recreclt

Description: Given a positive number A , construct a new positive number less than both A and 1. (Contributed by NM, 28-Dec-2005)

Ref Expression
Assertion recreclt A 0 < A 1 1 + 1 A < 1 1 1 + 1 A < A

Proof

Step Hyp Ref Expression
1 recgt0 A 0 < A 0 < 1 A
2 gt0ne0 A 0 < A A 0
3 rereccl A A 0 1 A
4 2 3 syldan A 0 < A 1 A
5 1re 1
6 ltaddpos 1 A 1 0 < 1 A 1 < 1 + 1 A
7 4 5 6 sylancl A 0 < A 0 < 1 A 1 < 1 + 1 A
8 1 7 mpbid A 0 < A 1 < 1 + 1 A
9 readdcl 1 1 A 1 + 1 A
10 5 4 9 sylancr A 0 < A 1 + 1 A
11 0lt1 0 < 1
12 0re 0
13 lttr 0 1 1 + 1 A 0 < 1 1 < 1 + 1 A 0 < 1 + 1 A
14 12 5 10 13 mp3an12i A 0 < A 0 < 1 1 < 1 + 1 A 0 < 1 + 1 A
15 11 14 mpani A 0 < A 1 < 1 + 1 A 0 < 1 + 1 A
16 8 15 mpd A 0 < A 0 < 1 + 1 A
17 recgt1 1 + 1 A 0 < 1 + 1 A 1 < 1 + 1 A 1 1 + 1 A < 1
18 10 16 17 syl2anc A 0 < A 1 < 1 + 1 A 1 1 + 1 A < 1
19 8 18 mpbid A 0 < A 1 1 + 1 A < 1
20 ltaddpos 1 1 A 0 < 1 1 A < 1 A + 1
21 5 4 20 sylancr A 0 < A 0 < 1 1 A < 1 A + 1
22 11 21 mpbii A 0 < A 1 A < 1 A + 1
23 4 recnd A 0 < A 1 A
24 ax-1cn 1
25 addcom 1 A 1 1 A + 1 = 1 + 1 A
26 23 24 25 sylancl A 0 < A 1 A + 1 = 1 + 1 A
27 22 26 breqtrd A 0 < A 1 A < 1 + 1 A
28 simpl A 0 < A A
29 simpr A 0 < A 0 < A
30 ltrec1 A 0 < A 1 + 1 A 0 < 1 + 1 A 1 A < 1 + 1 A 1 1 + 1 A < A
31 28 29 10 16 30 syl22anc A 0 < A 1 A < 1 + 1 A 1 1 + 1 A < A
32 27 31 mpbid A 0 < A 1 1 + 1 A < A
33 19 32 jca A 0 < A 1 1 + 1 A < 1 1 1 + 1 A < A