Rationals were already supported, but their input syntax was the same as for
reals: Decimal fixed point notation. This is now fixed and the functor X^-
allows weights to be written as either integers or ratios of integers, separated
by a slash.

This highlights the fact that they represent finite sets and the value syntax
are hexadecimal unsigned integers.

Fixes a syntax error that prevented this example from being parsed.

Corrects some typos and fixes the stack command used to execute the examples.

The same principle as when splitting blocks applies: The largest doesn't
have to be in the queue, because we already refine with respect to it
when refining the second-to-last block.

The block order changed in recent commits. The result is still
equivalent, but just ordered differently.

After the recent change to `deleteLargestM`, the order of blocks
changed for some examples.

The last commit changed the order of blocks in the final output for
one example.

Allow to use the unicode codepoint "LETTER CAPITAL P WITH HOOK" as
powerset functor symbol.

All files in examples/ now have a corresponding .out-file that is
checked against the algorithm's output on that example as part of the
test-suite.

Switches from X^G to G^X. The former would have been the syntax for a
mapping from the monoid, not into the monoid...

This switches the parser for functor expressions (not yet morphisms)
from a YAML based one to a custom one, making those expressions much
more readable and giving individual functors greater flexibility to
define their own syntax.