Here's a
guess at what you might need to do:
private DocumentationLink getadl(AContext ctx, APIDocumentationTypes a)
{
var adl = ctx.APIDocumentationTypes.Where(x => x.DocumentationTypeId == a.DocumentationTypeId)
.Select(x => x.DocumentationDescription.ToLower())
.FirstOrDefault(
descr => !(descr == "value1" || descr == "value2")
);
return (adl == "") ? null : a.DocumentationLink;
}
Of course, you can create "intermediate" variables in a 'Select query, if necessary/