We propose a method for obtaining the implication conditions of the properties of a mathematical model of a system from the structurally close properties of a model of another system related to the former one by cross-model linking objects. This method is applicable to various models and their properties. Any implication conditions for the properties are not required to be given a priori. They are formed during the solving corresponding logical equation with the possibility to broadly vary the cross-model linking objects. Usually, implication theorems obtained by this method are new or modifications of known ones. In other cases, they are corollaries or generalizations of known theorems. We provide detailed application examples for this method and interpret the conditions of the obtained theorems.