1.
|
Which
of the following are truth functors? Where the expression is a truth-functor,
what is its truth-table? Where it is not a truth-functor what is
its partial truth-table? (A partial truth-table is a truth-table
in which some rows have a "?" in them; in these cases,
think of pairs of examples to show that sometimes the resulting
sentence will be true in these cases and sometimes the resulting
sentence will be false.)
|
|
(i)
|
j
or y or both. |
(ii)
|
It
is true that j |
(iii)
|
It
is a necessary truth that j |
(iv)
|
It
could have been the case that j |
(v)
|
j,
but not because y |
(vi)
|
It
is true that j or it isn't |
(vii)
|
j,
but grass is not green |
(viii)
|
j,
whether or not grass is green |
(ix)
|
Everyone
knows that it is true that j or it isn't |