v0.3.0

• nested <= \elim discharges unreachable cases at every depth
• nested pattern (e.g. cons a (cons b c))
• \operator templates accept Unicode characters (e.g. \x ◁ \y)
• \elim auto-discharges unreachable constructor cases, so the user no longer has to write a clause asserting impossibility
• pretty-printer for kernel terms, used to render diagnostic messages

Full Changelog: v0.2.1...v0.3.0