Define and fix a complete Boolean algebra B and a first-order language L, which consists of a set of constant symbols, function symbols and relation symbols. Therefore, the Boolean model of L consists of the complete set M, which is a collection of elements (or names) and the explanations of these symbols. In particular, this model must assign an element of m to each constant symbol of L, and assign F and N tuples < a0, ..., an-1>; Every element in the model is assigned a value of m, and this model must assign m to the project f(a0, ..., an- 1).

The explanation of relational symbols and equations is more complicated: for each pair of elements A and B of M, the model must specify a true value for the expression A = B |||| A = B |||; This truth value is taken from B. Similarly, for each n-tuple symbol R and n-tuples

It is necessary to write some words to explain the additional limitations of the interpretation equation and ensure that it is equivalent, and this relationship considers the substitution of equivalent things.