Description: The empty category (see 0cat ) is thin. (Contributed by Zhi Wang, 17-Sep-2024)
Ref | Expression | ||
---|---|---|---|
Assertion | 0thinc | ⊢ ∅ ∈ ThinCat |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0ex | ⊢ ∅ ∈ V | |
2 | base0 | ⊢ ∅ = ( Base ‘ ∅ ) | |
3 | 0thincg | ⊢ ( ( ∅ ∈ V ∧ ∅ = ( Base ‘ ∅ ) ) → ∅ ∈ ThinCat ) | |
4 | 1 2 3 | mp2an | ⊢ ∅ ∈ ThinCat |