Request for Language: Language that compiles to Type Definitions

Let's make a Tree Language that compiles to "ts/d.ts" files. The compilation should be Type information only, not any Javascript code. The TypeScript should probably compile to a blank file.

Then we can write this file in this new Tree Language:
https://github.com/treenotation/jtree/blob/master/core/jTreeTypes.ts

Start by reading core/jTreeTypes.ts, the referenced TypeScript type-definition file, and clarify the proposed Tree Language and its output contract. Determine whether the goal is a .d.ts-only compiler or a blank TypeScript output, then define completion criteria for the language and generated type definitions.

Written by the indexing model from the issue text.