FUNCTIONAL_FORMS

compose:
* Function composition.  Feeds its input to the last function in its argument
* list, then feeds that function's output to the second-to-last, and so on,
* eventually returning the output of the last function in the list as the
* combined function's output.
*
* compose{ f, g } : x = f : (g : x)

construct:
* Sequence construction.  Feeds its input to each of its argument functions,
* and generate a sequence where each element is the output of one of the
* argument functions.
*
* construct{ f, g } : x  = < f : x, g : x >

if:
* Conditional form.  Accepts exactly three arguments.  First feeds its input
* to the first argument.  If the result is boolean True, it feeds the input to
* its second argument, if False then it feeds it to its third argument,
* otherwise it just returns Bottom.
*
* if{ f, g, h } : x = if f : x then g : x else h : x

map:
* Mapping functional form.  Accepts a single function argument.  Input to the
* form should always be in the form of a list, and the return value will be
* the result of applying the argument function to each element in the list.
*
* map{ f } : < x, y, z > = < f : x, f : y, f : z >

reduce:
* Reducing functional form.  Accepts a single function argument.  Expects
* input in the form of a list, return value is the result of first applying
* the argument function to a pair formed from the first two elements of the
* input list, then forming a new pair from that result and the next
* right-most element, and so on until the list is exhausted.
*
* reduce{ f } : < x, y, z > = f : < f : < x, y>, z >