public function find_formulas($text) {
        preg_match_all(self::FORMULAS_IN_TEXT_REGEX, $text, $matches);
        return array_combine($matches[1], $matches[1]);
    }
public function find_formulas($text) {
        preg_match_all(self::FORMULAS_IN_TEXT_REGEX, $text, $matches);
        return array_combine($matches[1], $matches[1]);
    }
public function find_formulas ( $ text ) { preg_match_all ( self :: FORMULAS_IN_TEXT_REGEX , $ text , $ matches ) ; return array_combine ( $ matches [ 1 ] , $ matches [ 1 ] ) ; }
Find all the formulas in a bit of text.

For example, called with "What is {a} plus {b}? (Hint, it is not {={a}*{b}}.)" this
returns ['{a}*{b}'].

@param $text text to analyse.
@return array where they keys an values are the formulas.
Find all the formulas in a bit of text .