interaction between temporal covariates in GEMACO

[Hoy]

Hi,

I am trying to run a model with a linear effect of age on survival [i + a(1_17)*x(3)] plus the main effects of two temporal covariates and an interaction between these two temporal covariates and have coded it like below.

Firstly is it ok to code for an interaction like this when one covariates spans a longer time period that the other.

[i + a(1_17)*x(3)]+[i + a(1_17)*x(3)]+[i+t(1_33)*x(1)].[i+t(4_33)*x(2)]

Secondly I get 5 Beta estimates for survival which is what I was expecting, but I am not sure which Betas relate to what effect when an interaction is involved. I assume from the coding above that

The 1st is the intercept for survival estimate
The 2nd the slope of survival with age
The 3rd the main effect of my first temporal covariate
The 4th the interaction between the first and second temporal covariate
The 5th the main effect of the second temporal covariate

or does the effect of the interaction came last?

Any help greatly appreciated

Thanks

Hoy

[CHOQUET]

I think that there is a mistake because [i + a(1_17)*x(3)] occurs twice.