The tests compile and pass again.
Box’s constructor & value are public.
Parse is zero terms.
Concatenation binds a little tighter.
Combinator types have labels.
Increase the precedence of reduction.
Style.
Test parsing terms.
Two-phase initialization dance for mutually recursive functions.
Correct literal parsing advance.
Test whitespace parsing.
Test IsZero parsing.
Equality for IsZero.
Flesh out equality.