Add math limit component (#2510)

src/file/paragraph/math/n-ary/math-limit-lower.ts

@@ -0,0 +1,19 @@
+// http://www.datypic.com/sc/ooxml/e-m_limLow-1.html
+import { XmlComponent } from "@file/xml-components";
+import { MathComponent } from "../math-component";
+import { MathBase } from "./math-base";
+import { MathLimit } from "./math-limit";
+
+export interface IMathLimitLowerOptions {
+    readonly children: readonly MathComponent[];
+    readonly limit: readonly MathComponent[];
+}
+
+export class MathLimitLower extends XmlComponent {
+    public constructor(options: IMathLimitLowerOptions) {
+        super("m:limLow");
+
+        this.root.push(new MathBase(options.children));
+        this.root.push(new MathLimit(options.limit));
+    }
+}