What make the new languages important are many other features for which no portmanteau description has yet emerged. It was to be in the public domain, and it was to incorporate those new features which the committee felt had proved themselves useful. It is a commonplace observation that the evolution of programming languages has been a continuing accommodation to the needs of human psychology. The educational aspect is not so much the evaluation of particular expressions, but what the student has to define to make that expression have meaning. Classes and constructors for types or values begin with a capital letter.
Variables begin with a lower case letter.
Comments are introduced by - . Suppose that we were giving a course that starts from Peano's axioms for the natural numbers and builds up to a description of the real numbers as a complete ordered field. When you have defined integers in terms of Nat you might as well come clean and switch to the more efficient built-in datatype Int. The progression to rational numbers, etc requires successively richer subclasses. Then you can compare the use of floating point numbers, interval arithmetic, Cauchy sequences and Dedekind cuts.