Access a variable in a different layer?

Is there a way to access a variable in a different layer?

Example:

Layer 1 expression:

x1=v*time;

.....

Layer 2 expression:

//something like this

anotherLayerX1 = thisComp.layer("1").GetVariable(x1);

thisComp.layer("1").SetVariable(x1, anotherLayerX1+10);