What are OCaml variants? What features do they subsume from imperative languages such as C and Pascal? What is the difference between normal-order and applicative-order evaluation? What is lazy...

What are OCaml variants? What features do they subsume from imperative languages such as C and Pascal? What is the difference between normal-order and applicative-order evaluation? What is lazy evaluation? What is the difference between a function and a special form in Scheme? What does it mean for a function to be strict?