The logic expression (X + Y + Z).(X + Y + Z′) is called

Concept

In Boolean algebra a Sum-of-Products (SOP) expression is an OR of AND-terms, while a Product-of-Sums (POS) expression is an AND (product) of OR-terms (sum terms). A POS becomes a standard (canonical) POS when every sum term is a maxterm, i.e. each sum term contains every variable of the function exactly once, either in true or complemented form.

Applying it here

• The expression is (X + Y + Z)·(X + Y + Z′): two sum terms joined by AND (·), so the outer operation is a product of sums — a POS form.

• Sum term (X + Y + Z) contains all three variables X, Y, Z; sum term (X + Y + Z′) also contains all three (Z appears complemented). Each term therefore holds every variable exactly once — each is a maxterm.

• Because every sum term is a maxterm, the product is in canonical / standard POS form, not merely a general POS.

Cross-check / contrast

• SOP would be an OR of AND-terms such as X·Y + X·Z; the given expression is the opposite arrangement, so any SOP label is ruled out.

• Plain “POS” is correct in spirit but less precise: it does not require full variables in every term. Since every term here is already a complete maxterm, the exact classification is the canonical/standard POS.

Hence the expression is in Standard POS form.