Terms containing it is one of the weaknesses of pictures that proofs of such an equality are difficult to conduct

Subject	English	Russian
progr.	it is one of the weaknesses of pictures that proofs of such an equality are difficult to conduct pictorially	Одна из слабостей графического представления, однако, состоит в том, что доказать такое равенство графически очень трудно (см. Communicating Sequential Processes by C.A.R. Hoare 1985 ssn)