6.9.1 Bottom Up

Play!

Play with the bottom-up recognizer (defined in bottomup_recognizer.pl ). Make sure you thoroughly understand how it works. In particular, make sure you understand

• the way append/3 is used to divide the input list into three sublists;

• why it is so slow!

We have provided two grammars for you to test it with, namely:

We have also provided a file

bottomup_recognizer_tests.pl: View Download

which contains examples for you to cut-and-paste to help you test.

6.9.2 Top Down

Make sure!

• Make sure you thoroughly understand how the top-down recognizer (topdown_recognizer.pl: View Download ) works. Test it with ourEng.pl. You will find examples to cut-and-paste in topdown_recognizer_tests.pl: View Download . Compare its performance with the naive bottom-up recognizer from the last section.

• Make sure you thoroughly understand how (topdown_parser.pl: View Download ) works. Test it with the ourEng.pl You will find examples to cut-and-paste in topdown_parser_tests.pl: View Download .

• Extend ourEng.pl so that noun phrases may contain adjectives. E.g. ``The dangerous robber died'' should be accepted by the grammar.