// test modification of a substring after an assignment.

var a := "testvalue";
var b := "value2";
var c := "value";

print( "a="+a );
print( "b="+b );
print( "c="+c );

var d := a["val"];

    // This is key: this assignment must not modify 'a'.
d := "hello";

print( "a="+a );
print( "d="+d );

    // Now, this one _should_.
a["val"] := "hello";

print( "a="+a );
print( "d="+d );