The Lambda
This is supposedly the lambda calculus version of the natural number game but lacking good lambda calculus library to parse, check, including every other process needed. this is still in demo.
The issue is that a function of certain goal can have multiple forms, hence harder to judge by comparing function. The grading method for solution might need to be case-based like competitive programming grader. For example, boolean and function can look like either lambda p. lambda q. p q p or lambda p. lambda q. p q lambda x. lambda y. y This two function is not similar (?) regardless of variable names.
This game is initially planned to guide player through the creation of boolean, number, and data-structure in the world of lambda calculus, which the side tracks might include SK-calculus or calculus in other basis. However, the basic of grading and interpreting lambda string is still problematic