on the paper "Mixed computation and program verification" by A.V. Grokh; a covering letter, memo and information about confidential data used in this paper are enclosed

on the paper "On the essence of mixed computation" by S.S. Lavrov; enclosed is the author's information about confidential data used in this paper

on the paper "Proof transformations as program transformations" by N.N. Nepeivoda

on the paper "The problems of mixed computation correctness illustrated by the INCOL language" by T.I. Yuganova