Halliday & Matthiessen (1999: 104-5, 105n):
There is another important difference between propositional logic and the natural logic of sequences. While there is only a very small handful of truth-functional connectives in propositional logic (conjunction, disjunction [exclusive or non-exclusive], implication), there is a very wide range of sequential relations in language — all the more specific varieties of projecting and expanding. A summary of these is given in Table 3(1).
² Projecting figures of the 'think' type — 'know', 'believe', 'want — have been represented outside standard logic within intensional logic.