There are certain customs that G must obey to be a standard American puzzle. (See Figure 3.37, for example.) Rewrite the informally stated conditions that follow as fully formal definition 1. no...

There are certain customs that G must obey to be a standard American puzzle. (See Figure 3.37, for example.) Rewrite the informally stated conditions that follow as fully formal definition

1. no unchecked letters: every open cell appears in both a down word and an across word.

2.no two-letter words: every word has length at least 3.

3.rotational symmetry: if the entire grid is rotated by 180◦

, then the rotated grid is identical tothe original grid