Function compiledProbe

src/compute-engine/symbolic/limit.ts:701–719

(
  e: Expression,
  x: string,
  ce: ComputeEngine
)

  if (op === 'Erf' || op === 'Erfc') {
    const inner = limitAtPosInf(o1(e), x, ce, depth + 1);
    if (!inner) return undefined;
    if (inner.isInfinity === true) {
      // Only a *signed* real infinity saturates. A directionless infinity
      // (e.g. ComplexInfinity) has neither `isPositive` nor `isNegative` set —
      // stay symbolic rather than defaulting to the +∞ branch (mirrors the
      // Sqrt/Root guard above).
      if (inner.isPositive === true) return op === 'Erf' ? ce.One : ce.Zero;
      if (inner.isNegative === true)
        return op === 'Erf' ? ce.number(-1) : ce.number(2);
      return undefined;
    }
    if (isDefiniteValue(inner)) return ce.function(op, [inner]).evaluate();
    return undefined;
  }

  return undefined;
}

function limitRatioAtPosInf(
  num: Expression,
  den: Expression,
  x: string,