Function factorial

src/compute-engine/library/combinatorics.ts:361–369

(m: number)

        if (!a || !k || a.isNaN || k.isNaN) return 'number';
        if (a.isFinite === false || k.isFinite === false) return 'number';
        if (k.isInteger === true && k.isNonNegative === true) {
          if (a.isInteger === true) return 'finite_integer';
          if (a.isRational === true) return 'finite_rational';
          if (a.isReal === true) return 'finite_real';
        }
        return 'number';
      },
      evaluate: ([a, k], { engine: ce }) => evaluatePochhammer(a, k, ce),
    },
    CartesianProduct: {
      description: 'Return the Cartesian product of input sets.',
      // Aka the product set, the set direct product or cross product