import proveit
# Prepare this notebook for defining the common expressions of a theory:
%common_expressions_notebook # Keep this at the top following 'import proveit'.
from proveit import Variable
from proveit.linear_algebra.inner_products.hilbert_spaces import (
HilbertSpacesLiteral)
%begin common
HilbertSpaces = HilbertSpacesLiteral()
Use $\mathcal{H}$ as a generic Hilbert space:
Hspace = Variable('H', r'\mathcal{H}')
%end common