The BOOL* language implementation using Scala

This is the language implementation for BOOL*

Language Specification:

e ::= True
    | False
    | if e then e else e

v ::= True
    | False

Big Step operational semantics:

• Rule#1

    e1 ⇓ True       e2 ⇓ v
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯       [BS - IF - True]
if e1 then e2 else e3 ⇓ v

• Rule#2

    e1 ⇓ False      e3 ⇓ v
⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯      [BS - IF - False]
if e1 then e2 else e3 ⇓ v

• Rule#3

v ⇓ v