Printing <cf> and <u> should not be allowed for two-valued structures

[Bart Bogaerts]

f<ct> = {}

f<u> = {}

is very confusing As you see two lines for f, this gives the impression that the structure is in fact three-valued...

[Broes De Cat]

It is indeed confusing, but some (preferably different) syntax should be available to allow minimal encoding size.

[Bart Bogaerts]

Solution: simply disable this behavior, and later maybe make it an option (if desired...)

[Bart Bogaerts]

Simplified printing of structures

Removed the possibility to print <cf> and <u> depending on table sizes. This was confusing for many users.

Maybe in the future we can make this kind of printing an option (if many people want it). For now, if you have too large ct-tables, you can manually print the cf table.

Fixes #551

→ <<cset 9d57dfc8e7a8>>