# LOGIC concepts

#### Ryan$##### Junior Member Hi guys ; Can someone please illustrate me what does the word "only" mean in terms of math? I mean lets assume someone told me "only motorcycles can enter this gate" so what should I understand from this? I'm really new on logic and frankly I'm not good as much as in math so please take that into consideration and I know all person has its own ability of understanding/learning. thanks #### tkhunny ##### Moderator Staff member Hi guys ; Can someone please illustrate me what does the word "only" mean in terms of math? I mean lets assume someone told me "only motorcycles can enter this gate" so what should I understand from this? I'm really new on logic and frankly I'm not good as much as in math so please take that into consideration and I know all person has its own ability of understanding/learning. thanks You can gain some understanding by moving it. "only motorcycles can enter this gate" "motorcycles only can enter this gate" "motorcycles can only enter this gate" "motorcycles can enter only this gate" "motorcycles can enter this only gate" "motorcycles can enter this gate only" Which ones don't make sense? What should you not be modifying? How does the meaning change with each one that does make sense? #### pka ##### Elite Member Hi guys ; Can someone please illustrate me what does the word "only" mean in terms of math? I mean lets assume someone told me "only motorcycles can enter this gate" so what should I understand from this? I'm really new on logic and frankly I'm not good as much as in math so please take that into consideration and I know all person has its own ability of understanding/learning. Ryan$, 'only' is not a mathematical nor a logical term in and of itself.
The construction only if, has an important role to play in logic. Consider the sentence: "One may enter by way of this gate only if he/she is riding a motorcycle." That sentence means that if George enters by this gate then he does so riding his motorbike. The rule is: P only if Q is equivalent If P then Q.

#### Dr.Peterson

##### Elite Member
Can someone please illustrate me what does the word "only" mean in terms of math? I mean lets assume someone told me

"only motorcycles can enter this gate" so what should I understand from this? I'm really new on logic and frankly I'm not good as much as in math so please take that into consideration and I know all person has its own ability of understanding/learning.
This is as much English as math. You have to think about what logical statement has the same meaning.

You will be writing something like "If _____, then _____". What has to go in each blank in order to mean "Only motorcycles can enter this gate"?

If this is a problem you were assigned, it may be helpful to look at answers given to similar examples or exercises, to see what form is expected; please show them to us, so we can be sure we are leading you in the right direction!

#### Jomo

##### Junior Member
thanks to you all, I got the point behind!