例句與造句

1. Indeed, it is fairly easy to construct a finitely generated recursively presented group with undecidable word problem.
2. Every finitely presented group is recursively presented, but there are recursively presented groups that cannot be finitely presented.
3. From this we can deduce that there are ( up to isomorphism ) only countably many finitely generated recursively presented groups.
4. As a corollary, there is a "'universal finitely presented group "'that contains " all " finitely presented groups as subgroups ( up to isomorphism ); in fact, its finitely generated subgroups are exactly the finitely generated recursively presented groups ( again, up to isomorphism ).
5. The related but different "'uniform word problem "'for a class " K " of recursively presented groups is the algorithmic problem of deciding, given as input a presentation " P " for a group " G " in the class " K " and two words in the generators of " G ", whether the words represent the same element of " G ".
6. It's difficult to find recursively presented group in a sentence. 用recursively presented group造句挺難的