Only a matter of context

In the above sentences we can witness a difference in truth conditions that seems to be associated with focus. In a situation in which Jane introduced Carol to Robert and Jacky, and there were no other introductions, sentence (la) will be true, whereas (lb) will be false. Yet, Vallduví (1990) shows that only does not have to be associated with focus. The truth-conditional difference between (la) and (lb) does not necessarily depend on focus, but rather on what is considered the semantic argument of only. In most cases focus will indicate what is the argument of only, but not always. Suppose we supply the following context: I know that Jane introduced Carol and Jacky to Peter and that Jane introduced Carol (but not Jacky) to someone, but I do not know who is this someone. In this context I can ask: Who did Jane only introduce [Carol]F to, and the answer will be (lb) rather than (la). So, only will then be associated with Carol, in the sense that Jane introduced only Carol and noone else to Robert, although Robert is the element in focus.