NARS APL: Rational representation and numerator

Question

In NARS, fractions are represented using r example 23r45 will be the fraction 23⁄45. The problem is, if I have a variable that contains a rational number, how do I access the numerator? Does a "numerator" function exist such that numerator 23r45 returns 23?

Answer 1

There is no built-in "numerator" function, but you can easily construct one:

      num←(⊣÷∨)∘1
      num 23r45
23 

For reference, the denominator can be found with:

      den←(⊢÷∨)∘1
      den 23r45
45

And so you can "split" a rational with:

      n_d←(,÷∨)∘1
      n_d 23r45
23 45