Implement FTC

[Bubbler-4]

• Proof-of-concept ULC interpreter in Rust
• Make the interpreter fast
• Proof-of-concept ULC to SKI compiler in Rust
• Make the SKI short
• ULC to BLC, GodelLC and back to ULC
• SKI to BCL, Unlambda, Iota, Jot and back to SKI or ULC
• Publish the above as a sub-crate
• FTC syntax parser
• FTC to ULC compiler
• ULC term formatter

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Somehow it feels like a combinator graph reduction machine (also related: Ben Lynn's work) can be significantly faster than directly operating on ULC terms. (We can avoid up to O(n^3) size bloat by using other combinators like Bn or Cn, or supercombinators.) (Also looks like the former lends itself well to things like typed_arena.)

List of literatures behind GHC