GetInterFrameSpacingFor(nsPresContext* aPresContext, PRInt32         aScriptLevel,
GetInterFrameSpacingFor(PRInt32         aScriptLevel,
GetInterFrameSpacingFor(nsPresContext* aPresContext,                        PRInt32         aScriptLevel,                        nsIFrame*       aParentFrame,                        nsIFrame*       aChildFrame){  nsIFrame* childFrame = aParentFrame->GetFirstChild(nsnull);  if (!childFrame || aChildFrame == childFrame)    return 0;  PRInt32 carrySpace = 0;  eMathMLFrameType fromFrameType = eMathMLFrameType_UNKNOWN;  nsIAtom* childFrameType = childFrame->GetType();  nsIAtom* prevFrameType = nsnull;  childFrame = childFrame->GetNextSibling();  while (childFrame) {    prevFrameType = childFrameType;    childFrameType = childFrame->GetType();    nscoord space = GetInterFrameSpacing(aScriptLevel,      prevFrameType, childFrameType, &fromFrameType, &carrySpace);    if (aChildFrame == childFrame) {      // get thinspace      nsStyleContext* parentContext = aParentFrame->GetStyleContext();      const nsStyleFont* font = parentContext->GetStyleFont();      nscoord thinSpace = NSToCoordRound(float(font->mFont.size)*float(3) / float(18));      // we are done      return space * thinSpace;    }    childFrame = childFrame->GetNextSibling();  }  NS_NOTREACHED("child not in the childlist of its parent");  return 0;}