BoolTool: A Tool for Manipulation of Boolean Functions

A new tool for manipulation of logic functions is presented in this paper. The source functions are described by an algebraic expression (or a set of expressions), in a VHDL-like style, by a truth table (PLA) or as a CNF form. In particular, any multilevel network of logic gates can be used as a source for the tool. The tool is capable of performing basic Boolean operations on the source functions, like negating the function, performing AND, OR, XOR operations, etc., between two or more functions. Then, the tool is able to mutually transform the CNF and DNF function representations, which also enables to solve a satisfiability (SAT) problem as a byproduct. Last, but not least, the tool performs a function collapsing, i.e., it transforms a multi-level Boolean network into its two-level description (truth table). Some Boolean operations, like computing a negation of a function in DNF, are rather time and memory consuming. For this reason a special structure called a “ternary tree” is introduced. The ternary tree is used to store the function’s terms and to perform a basic minimization of the function representation. Basic principles of the ternary tree representation of a function and its minimization principles are described in this paper too. The proposed tool was tested on several different problems (minimization of a function, SAT solving, collapsing) and compared with state-of-the-art tools.