When creating a parser, look-ahead sets are calculated for all productions in the grammar. Normally this is a reasonably quick operation, but in some extreme cases it can be very slow due to inherent ambiguities in combination with a combinatorial explosion. When look-ahead sets starts growing to sizes of more than a thousand entries, the look-ahead calculation in general slows down to a crawl.

Currently the --debug mode and others do not print anything during this phase, which leads the user into thinking that Grammatica has entered an infinite loop. This should be remedied by either changing the --debug mode to print information on conflicts while the look-ahead calculation is being done, or by adding a new --verbose flag that causes such printouts to occur.