A product of two of these expressions is scaled by the Jastrow correlation factor. CAS methods construct an active space spanned by “m choose n-up” times “m choose n-down” of these expressions. Heiter and London defined as a bond in modern VBT as the difference between two of these expressions denoted “a, b-overbar” and “a-overbar b.” These expressions do not form an eigenbasis of S-hat-squared but are still used to construct excitations in multi-reference (*) CI. Just one of these multi-term expressions, (10[1])normalized by one-over-root N-factorial, (10[2]-5[2])approximates a high-N wavefunction in Hartree-Fock by ensuring the probability (10[1])vanishes when two orbitals match. For 10 points, the exchange antisymmetry (10[1]-5[1])of multi-electronic wavefunctions is guaranteed (10[1])by what expressions, (10[1])which involve an operation performed on square matrices? (10[1])■END■ (10[1]0[3])