Quick grouping game diagramming question Forum

[flem]

This is probably simple, but I need someone to explain this to me. I'm usually good with necessary/sufficient type stuff but this rule is weird. Maybe it's because I've been at work all day.

Roughly:

In order for X to be picked, Y must be picked.

Intuitively it seems that this would be diagrammed as:

Y ------> X

However, the correct representation of this rule is apparently:

X ------> Y

Can someone please break down why I am retarded?

[Campagnolo]

This is probably simple, but I need someone to explain this to me. I'm usually good with necessary/sufficient type stuff but this rule is weird. Maybe it's because I've been at work all day.

Roughly:

In order for X to be picked, Y must be picked.

Intuitively it seems that this would be diagrammed as:

Y ------> X

However, the correct representation of this rule is apparently:

X ------> Y

Can someone please break down why I am retarded?

Y must be picked. That makes it necessary and therefore the condition on the right. Sometimes the contrapositive makes more sense: If Y is not picked, what about X?

[rinkrat19]

Because you can have Y without having X, but you can't have X without Y.

[timmydoeslsat]

In order for X to be picked, Y must be picked.

Just think about what you know to be true from that statement.

What happens if we have X?

We would have to have Y. Therefore, X ---> Y

[flem]

Thanks all