Permutation has the exchanges codice_34. If we assume the exchange codice_35 is unsteckered, that implies exchanges codice_36. The other five permutations can be quickly checked for an unsteckered pair that is consistent with interchanging codice_36 — essentially checking column codice_38 for other rows with codice_39 without computing the entire table. None are found, so codice_35 would have at least one stecker so the assumption it is unsteckered is abandoned. The next pair can be guessed as unsteckered. The exchange codice_41 implies exchanges codice_42; that is consistent with codice_43 in , but that guess fails to pan out because codice_44 and codice_45 are steckered.