Define Canonical form of an expression with respect to its Cardinal form.

The Canonical form of a Boolean expression is its complete standard form - canonical SOP (sum of minterms) or canonical POS (product of maxterms) - in which every term contains all the variables of the function, each appearing either in true or complemented form. The Cardinal form is simply the compact shorthand way of writing this canonical form: it lists only the decimal numbers of the minterms/maxterms using the symbol $\Sigma$ (for sum of minterms) or $\Pi$ (for product of maxterms), e.g. $F(A,B,C)=\Sigma m(1,3,7)$ is the Cardinal form of the canonical SOP $A'B'C + A'BC + ABC$.