Score | Comments |
8 | For (1c), it is true that division is not associative, but this
isn't what they are supposed to be considering. Proof omits (6f). |
10 | Small mistake on division in associativity proof. |
6 | no proofs, the second part is a "proof by example". |
7 | In (1c) they are working with the wrong operation. In (6) they don't check the closure operation. |
10 | We say "…is closed under addition" not "…is close under addition". |
Score | Comments |
8 | Proof never draws the conclusion it needs to in order to complete the problem. |
5 | The proof repeats part of what is supposed to be proved but makes no reference to t(G) or its complement. |
7 | The language is imprecise. For example the word "pair" is not properly defined in the way that it is used. |