📝N×M problem

N×M problem arises where you have N things that should combine with other M things.

Examples are:

• N languages that need to be compiled into M machines architectures (e.g., solved by LLVM IR)
• N editors that need to implement support for M languages (solved by language server)
• N transformation algorithms that need to work on M data structures (Transducers, Foldable(?))