Understanding a calc script

Hyperion Planning

11.1.2.4.010.05

I'm fairly new to reading calc scripts. What are these two statements telling me?

I appreciate any help. Lisa

FIX({MRRStartYearVar},{MRRStartMonthVar}:"Dec")

"Subs SaaS Retained MRR" = "Subs SaaS Run Off Amt for Renewal" + "Subs SaaS Retained Amt for Renewal" + "Subs SaaS MRR CPI" + "Subs SaaS MRR Attrition";
"Subs SaaS CPI Total"(
IF(@ISMBR({MRRStartMonthVar}))
"Subs SaaS CPI Total" = "Subs SaaS MRR CPI";
"Subs SaaS Attrition Total"= "Subs SaaS MRR Attrition";
ELSE
"Subs SaaS CPI Total" = @PRIOR("Subs SaaS CPI Total") + "Subs SaaS MRR CPI";
"Subs SaaS Attrition Total" = @PRIOR("Subs SaaS Attrition Total") + "Subs SaaS MRR Attrition";