Function expComplexNum

test/compute-engine/canonical-form.test.ts:807–814

(
          expr: string | ExpressionInput,
          type?: NumericType
        )

          {num: "358796515092200247647243"}
        ]
        canonical  = [
          "Rational",
          {num: "-318982460862894267352492496399"},
          {num: "358796515092200247647243"}
        ]
      `);
      expect(canonNumber(bigRational).operator).toBe('Rational'); // ✔

      /*
       * Control
       */