# Prepare this notebook for defining the common expressions of a theory:
%common_expressions_notebook # Keep this at the top following 'import proveit'.
Defining common sub-expressions for theory 'proveit.logic.booleans.negation'
Subsequent end-of-cell assignments will define common sub-expressions
%end_common will finalize the definitions
Theory proveit.logic.booleans.negation has no common expressions