/Я language (β)/Primitives/Prefix Tree/

: Supertype ( Prefix Tree i ii ) ~ ( Prefix List ( Construction ( Prefix List i ) ii ) )
: Basetype ( Prefix Tree i ii ) ~ ( Unit `S` List ( Supertype ( Construction ( Prefix List i ) ii ) ) )

> `yo` : a o . Prefix Tree i a `AR_____` a `AR____` o `AR____` Prefix Tree i o