any() and all() are popular functions for filtering a set based on membership of subcollections. These functions are part of the ABNF construction rules but are not described anywhere and do not appear in the list of canonical functions that can be used in $filter/$sort.
http://host/service.svc/Orders?$filter=OrderLines/any(ol: ol/Quantity gt 10)
returns Orders that have any Orderlines with a Quantity greater than 10.
http://host/service.svc/Orders?$filter=OrderLines/all(ol: ol/Quantity gt 10)
returns Orders for which all Orderlines have a Quantity greater than 10.