Base 5 (3M+2F)                           => PASS
Base 5 + 1 sub                           => PASS
Invalid base 4M+1F                       => FAIL: base composition invalid (requires 3M+2F or 2M+3F)
Two substitutes                          => FAIL: total > 6
Sub before base 5                        => FAIL: substitute before base 5
Base > 5                                 => FAIL: base > 5
Total > 6                                => FAIL: total > 6