Hi all

Here is a piece of PHP code making substitutions in elements of an array $this->_equations :

```
for ($i = ($currentEquationRank + 1); $i < $nbrEquations; $i++) {
logError("i", $i);
logError("this->_equations[0] avant substitution", $this->_equations[0]->displayEquation());
$this->_equations[$i]->substitutionInTerms(
$this->_equations[$currentEquationRank]->getType1(),
$this->_equations[$currentEquationRank]->getType2()
);
logError("this->_equations[0] après substitution", $this->_equations[0]->displayEquation());
}
```

When i=18, my log reports:

```
this->_equations[0] avant substitution
{"boundVar":0} = {"baseType":"P"}
this->_equations[0] après substitution
{"baseType":"P"} = {"baseType":"P"}
```

I don’t understand why this->_equations[0] would change while we are acting on another element of the array.

Here is below the code of the functions getType1 and getType2 ($this->_type1 and $this->_type2 are arrays supposed to be cloned in $res):

```
public function getType1()
{
$res = $this->_type1;
return $res;
}
public function getType2()
{
$res = $this->_type2;
return $res;
}
```

Would someone have hints to make me understand please ?