Lawgic Question

Abset710

Hello everybody,

I was wondering if anybody could help clarify something for me. I am a little confused about diagramming the sentences with two "if (or unless)". How could I translate the following sentence into the formal lawgic?

"no plant is worth growing unless it bears fruit"

I tried this way " - bears fuits ----> (P ---> - WG) " but this structure is not helpful.

Is it okay to translate this into either one of the following?
" -bears fruits ---> P ---> --WG" or " - bears fruits + P ---> - WG"

Can anyone shed some light on this?

P.S: Please helpe me with the next one too
"New investment that takes place while interest rates are falling cannot lead to the huge growth"

harrismegan

Plant WG ----> BF

GSU Hopeful

For the second second sentence, I would diagram it NI ---> /HG.

The "that takes place while interest rates are falling" is the modifier explaining what kind of new investments we are talking about. Cannot is group four (negate, necessary) which leads to the negation of the "huge growth."

I might be wrong, but this is how I did it.

Alex Short

No plant is worth growing unless it bears fruit.

So this unless statement is pretty simple - the sufficient condition (WG) is already negated with "No...", so you end up with the same translation as though you had "If a plant is worth growing, then it bears fruit":

WG -> BF
~BF -> ~WG

c.janson35

In general, I think that it is easiest to remember that you can replace "unless" in a sentence with "if not" and keep the same logical meaning.

"I will go to the beach unless it rains"

"I will go to the beach if not it rains" or "I will go to the beach if it doesn't rain"

Then it's simple to diagram:
/R-->B