早期的熊能有多小?【犬形亚目-熊科-首鼬熊族】
∀x [ O(x) → ( A(id(x)) ∧ s(id(x)) = x ∧ t(id(x)) = x
∧ ∀f ( A(f) ∧ s(f)=x → f ∘ id(x) = f )
∧ ∀g ( A(g) ∧ t(g)=x → id(x) ∘ g = g ) ) ]
∀f∀g∀h [ A(f) ∧ A(g) ∧ A(h)
∧ t(h)=s(g) ∧ t(g)=s(f)
→ (f ∘ g) ∘ h = f ∘ (g ∘ h) ]
∀f∀g
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