---
title: "init(baseExpression:underExpression:overExpression:)"
framework: Accessibility
role: symbol
role_heading: Initializer
platforms: [iOS 18.2+, iPadOS 18.2+, Mac Catalyst 18.2+, macOS 15.2+, tvOS 18.2+, visionOS 2.2+, watchOS 11.2+]
path: "accessibility/axmathexpressionunderover/init(baseexpression:underexpression:overexpression:)"
---

# init(baseExpression:underExpression:overExpression:)

## Declaration

```swift
init(baseExpression: AXMathExpression, underExpression: AXMathExpression, overExpression: AXMathExpression)
```