it must be true that
-P--->-H
P--->H
why is P--->H the correct option?
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Re: #145 Wont have P unless it has H
"Won't have P unless it has H" means:
If P --> H
In other words, the NORMAL thing is not to have P. If P DOES happen, it means H has to have happened.
This is NOT a correct inference: ~P --> ~H
The valid contrapositive of P --> H is ~H --> ~P
If you are confused as to why, read the "Unless" portion of the Logical Reading Strategy Guide (Chapter 8) carefully to educate yourself on how to convert "unless" statements to "if...then" statements.
If P --> H
In other words, the NORMAL thing is not to have P. If P DOES happen, it means H has to have happened.
This is NOT a correct inference: ~P --> ~H
The valid contrapositive of P --> H is ~H --> ~P
If you are confused as to why, read the "Unless" portion of the Logical Reading Strategy Guide (Chapter 8) carefully to educate yourself on how to convert "unless" statements to "if...then" statements.
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