Strange behavior of HP prime pro app

[roadrunner]

Try not using built in variable names declared as local. Like this:

EXPORT RATIO()
BEGIN
LOCAL exx1,why1,arr,FL,EZ,SZ,exx,why;
INPUT(exx1,"MUE1=?");
INPUT(why1,"MUE2=?");
INPUT(arr,"CORR=?");
∫(√((1+why^2)/(1+arr^2))/2/π*∫(e^(−((exx-exx1)^2+(why*exx-why1)^2-2*arr*(exx-exx1)*(why*exx-why1))/(2*(1-arr^2))),exx,exx1-6,exx1+6),why,why1-6,why1+6)▶FL;
∫(why*√((1+why^2)/(1+arr^2))/2/π*∫(e^(−((exx-exx1)^2+(why*exx-why1)^2-2*arr*(exx-exx1)*(why*exx-why1))/(2*(1-arr^2))),exx,exx1-6,exx1+6),why,why1-6,why1+6)▶EZ;
EZ/FL▶EZ;
∫(why^2*√((1+why^2)/(1+arr^2))/2/π*∫(e^(−((exx-exx1)^2+(why*exx-why1)^2-2*arr*(exx-exx1)*(why*exx-why1))/(2*(1-arr^2))),exx,exx1-6,exx1+6),why,why1-6,why1+6)▶SZ;
√(SZ/FL-EZ^2)▶SZ;
PRINT("--------------------------------");
PRINT("MUE1=" +exx1);
PRINT("MUE2=" +why1);
PRINT("CORR=" +arr);
PRINT("FL=" +FL);
PRINT("EZ=" +EZ);
PRINT("SZ=" +SZ);
END;

I can't test this on your exact platform but it works on the simulator for windows 10.

-road