Method _fn

src/compute-engine/index.ts:1943–1951

* Return a function expression, but the caller is responsible for making * sure that the arguments are canonical. * * Unlike `ce.function()`, the operator of the result is the name argument. * Calling this function directly is potentially unsafe, as it bypasses * the canonicalization

(
    name: MathJsonSymbol,
    ops: ReadonlyArray<Expression>,
    options?: { metadata?: Metadata; canonical?: boolean; scope?: Scope }
  )

   * - `atan()`
   * - `cosh()`
   * - `sinh()`
   * - `acosh()`
   * - `asinh()`
   * - `atanh()`
   * 
   * - `isFinite()`
   * - `isInteger()`
   * - `isNaN()`
   * - `isNegative()`
   * - `isPositive()`
   * - `isZero()`
  * - `sign()` (1, 0 or -1)