∫ Утверждение Mathlib
card_mul_le_card_mul'
Mathlib.Combinatorics.Enumerative.DoubleCounting
URI: https://scilib.ai/kg/mathlib#Finset.card_mul_le_card_mul'
∫ Утверждение Mathlib
Mathlib.Combinatorics.Enumerative.DoubleCounting
URI: https://scilib.ai/kg/mathlib#Finset.card_mul_le_card_mul'