Metamath Proof Explorer


Theorem iccnct

Description: A closed interval, with more than one element is uncountable. (Contributed by Glauco Siliprandi, 3-Jan-2021)

Ref Expression
Hypotheses iccnct.a φ A *
iccnct.b φ B *
iccnct.l φ A < B
iccnct.c C = A B
Assertion iccnct φ ¬ C ω

Proof

Step Hyp Ref Expression
1 iccnct.a φ A *
2 iccnct.b φ B *
3 iccnct.l φ A < B
4 iccnct.c C = A B
5 eqid A B = A B
6 1 2 3 5 ioonct φ ¬ A B ω
7 ioossicc A B A B
8 7 4 sseqtrri A B C
9 8 a1i φ A B C
10 6 9 ssnct φ ¬ C ω