Metamath Proof Explorer


Theorem naddle

Description: Condition for bounding natural addition above. (Contributed by Scott Fenton, 21-Jul-2026)

Ref Expression
Assertion naddle A On B On C On A + B C a A a + B C b B A + b C

Proof

Step Hyp Ref Expression
1 ltnadd C On A On B On C A + B a A C a + B b B C A + b
2 1 3coml A On B On C On C A + B a A C a + B b B C A + b
3 2 notbid A On B On C On ¬ C A + B ¬ a A C a + B b B C A + b
4 naddcl A On B On A + B On
5 4 3adant3 A On B On C On A + B On
6 simp3 A On B On C On C On
7 ontri1 A + B On C On A + B C ¬ C A + B
8 5 6 7 syl2anc A On B On C On A + B C ¬ C A + B
9 simpl3 A On B On C On a A C On
10 onss A On A On
11 10 3ad2ant1 A On B On C On A On
12 11 sselda A On B On C On a A a On
13 simpl2 A On B On C On a A B On
14 12 13 naddcld A On B On C On a A a + B On
15 ontri1 C On a + B On C a + B ¬ a + B C
16 9 14 15 syl2anc A On B On C On a A C a + B ¬ a + B C
17 16 rexbidva A On B On C On a A C a + B a A ¬ a + B C
18 simpl3 A On B On C On b B C On
19 simpl1 A On B On C On b B A On
20 onss B On B On
21 20 3ad2ant2 A On B On C On B On
22 21 sselda A On B On C On b B b On
23 19 22 naddcld A On B On C On b B A + b On
24 ontri1 C On A + b On C A + b ¬ A + b C
25 18 23 24 syl2anc A On B On C On b B C A + b ¬ A + b C
26 25 rexbidva A On B On C On b B C A + b b B ¬ A + b C
27 17 26 orbi12d A On B On C On a A C a + B b B C A + b a A ¬ a + B C b B ¬ A + b C
28 rexnal a A ¬ a + B C ¬ a A a + B C
29 rexnal b B ¬ A + b C ¬ b B A + b C
30 28 29 orbi12i a A ¬ a + B C b B ¬ A + b C ¬ a A a + B C ¬ b B A + b C
31 ianor ¬ a A a + B C b B A + b C ¬ a A a + B C ¬ b B A + b C
32 30 31 bitr4i a A ¬ a + B C b B ¬ A + b C ¬ a A a + B C b B A + b C
33 27 32 bitrdi A On B On C On a A C a + B b B C A + b ¬ a A a + B C b B A + b C
34 33 con2bid A On B On C On a A a + B C b B A + b C ¬ a A C a + B b B C A + b
35 3 8 34 3bitr4d A On B On C On A + B C a A a + B C b B A + b C