Lean Mechanization of Capture Calculus

Currently it contains the mechanization of both System F<: and System CC<:box.

• fsub/, the System F<: type soundness proof. Intrinsically typed and de Bruijn indexed.
• CC/, the proof for System CC<:box. It is de Bruijn indexed and extrinsically typed. Main type soundness results (progress and preservation) are in CC/Reduction/Safety.lean.

The next step is to mechanize the soundness theorems of the separation calculus.