Description:
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Result of 'and' operator not what is expected. 1 and 0 and 1 => 1? Should be 0. See attached code sample. '&&' operator does function correctly however.

Reproduce code:
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    $primary_err_valid = (($_POST['primary_err'] != "category") and ($_POST['primary_err'] != "separator"));
    $secondary_err_valid = (($_POST['secondary_err'] != "category") and ($_POST['secondary_err'] != "separator"));
    $tertiary_err_valid = (($_POST['tertiary_err'] != "category") and ($_POST['tertiary_err'] != "separator"));
    $error_valid = ($primary_err_valid) and ($secondary_err_valid) and ($tertiary_err_valid);

	echo "Pri: $primary_err_valid <br>";
	echo "Sec: $secondary_err_valid <br>";
	echo "Tri: $tertiary_err_valid <br>";
	echo "Total Error: $error_valid <br>";


Expected result:
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Pri: 1
Sec: 
Tri: 1
Total Error: 

Actual result:
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Pri: 1
Sec: 
Tri: 1
Total Error: 1