index and find cmd

[compsystems]

Hello

Please try the following instructions on the hp-prime calculator:

index:=1:; E_ := [ "H", "E", "L", "L", "O" ]:; find( "L", E_ ); index(E_,"L"); [enter]
"Done","Done",[3,4],3 // ok

Now index -> 0
index:=0:; E_ := [ "H", "E", "L", "L", "O" ]:; find( "L", E_ ); index(E_,"L"); [enter]
"Done","Done",2,2

the output should be
"Done","Done",[2,3],2

index:=1:;index("abracadabrant","c") [enter] error // the output should be 5
index:=0:;index("abracadabrant","c") [enter] -1 // the output should be 4

Thanks