 The effect of implementing the INFORM as an utterance is then that the hearer knows whether X is true. An important feature of such a framework is that it can account for indirect speech acts (Allen and Perreault 1980). For example, question (7.1), as an indirect request for the date or day of the week, can be viewed as indicating the speaker's awareness that the hearer can perform the requested information-conveying act only if the knowledge-precondition of that act is satisfied. Furthermore, since the hearer recognizes that questioning a precondition of a potential act is one indirect way of requesting the act, then (unless the context provides evidence to the contrary) the hearer will make the inference that the speaker wants the hearer to perform the information-conveying speech act. Note that the reasoning and planning framework must allow for iterated modalities such as “I believe that you want me to tell you what today's date is”, or “I believe (because of the request I just made) that you know that I want you to pass the salt shaker to me”. Importantly, there must also be allowance for mutual beliefs and intentions, so that a common ground can be maintained as part of the context and collaboration can take place. A belief is mutual if each participant holds the belief, and the participants mutually believe that they mutually hold the belief. The mutual knowledge of the participants in a dialogue can be assumed to include the overt contents of their utterances and common general knowledge, including knowledge of discourse conventions.