How to model a t-1 function on vensim

[jdiab11]

I need to calculate several sensitivity and elasticities in my model, how can i tell vensim that i need a t-1 in an equation?
For instance, supposed i have X and Y linked, and Y = (X(t)-X(t-1))/X(t), how can i write this equation on vensim?

[tomfid]

Usually it's easiest to create something like:

Previous X = DELAY FIXED(x, one period, x)

More here:
https://metasd.com/2017/11/discrete-time-stinks/