# incredible something happen to me in math related to logic

#### Denis

##### Senior Member
As I told you earlier Ryan, we can't tell what you're asking ...

#### Ryan\$

##### Full Member
Please quote the actual problem you are working on here, in its entirety. That will make all the difference. In particular, we need to see whether these are two parts of one problem, or two separate problems; and we need to see what the goal is that they are asking you to accomplish. That is what can tell you whether it is legitimate to use one in the other.

A problem you have made up or simplified from something larger is not sufficient. Until you do that, there is really nothing to say.
My problem that if I have two equations, for instance:
(1) x=y
(2)x+f=z
once I arrive to the second equation, while I read the first equation, I know that x=y, but not assigning that although literally I know x=y from the first equation ! so what's that problem? am I have a mentally problem? I mean is it my mentally problem, or I need to practice to start think in another way?
once again I know that I must assign x=y when I read the second equation but my mind tells me to not assign ! how can I solve that problem?>!

#### Dr.Peterson

##### Elite Member
Please do what you are asked. We want to see an actual problem you found somewhere, not one that you have made up that would never be given. I can't answer you until you cooperate.

#### JeffM

##### Elite Member
Please do what you are asked. We want to see an actual problem you found somewhere, not one that you have made up that would never be given. I can't answer you until you cooperate.
I do not think that there is a real problem. I think Ryan thinks that he can understand generalizations without any reference to the specifics that the generalization represents. Without understanding the generalization, he tries to do so by making up problems purportedly involving the generalization. Needless to say, you cannot dispel ignorance through ignorance.

Ryan

$$\displaystyle x = y \text { and } x + f = z \implies y + f = z.$$

If that conclusion is helpful, you can use it.

#### HallsofIvy

##### Elite Member
Do you understand what "=" means?