“…Let L be the linear space generated by B = {1, t 1 , t 2 , t 1 t 2 } and let L T be the monomial standard evaluation code on T = A 1 × A 2 relative to the GRevLex order ≺. The vanishing ideal I = I(T ) of T is generated by t 3 1 − 1 and t 2 2 − 1, the index of regularity of H a I is 3, and the set of standard monomials of S/I is ∆ ≺ (I) = {1, t 1 , t 2 , t 2 1 , t 1 t 2 , t 2 1 t 2 }. According to Proposition 7.2 and Corollary 7.3, the algebraic dual L ⊥ is given by…”