58     protected $_context = null;  variable in Hoa\\Math\\Visitor\\Arithmetic
79         $old = $this->_context;
81         $this->_context = $context;
93         return $this->_context;
280         return $this->_context->getFunctions();
292         return $this->_context->getFunction($name);
302         return $this->_context->getConstants();
314         return $this->_context->getConstant($name);
324         return $this->_context->getVariables();
336         return $this->_context->getVariable($name);
341         if (null === $this->_context) {
342             $this->_context = new Math\Context();
357         return $this->_context->addFunction($name, $callable);
369         return $this->_context->addConstant($name, $value);
381         return $this->_context->addVariable($name, $callable);