Allow @ Instead of Unicodes Lambda (λ) and For All (∀)

## Descriptiopn

Currently, we use the Unicode λ (lambda) and ∀ (For all) symbol in the project to represent lambda expressions in our code. While this is the traditional notation, it can sometimes be inconvenient for those who don't have easy access to Unicode characters on their keyboard.

## Request:

I would like to propose allowing the @ symbol to be used as an alternative to λ and ∀ in the source code, as @ is more accessible on standard keyboards and still widely recognizable as a placeholder for functions or expressions.