If the knees of the models on the right and left are facing each other, and each model wears just one kneepad.
return models ;return #1 on the  right ;return #1 on the  left ;return knees of #2 ;return knees of #3 ;return if  #4 are facing #5 ;return kneepads ;return #7 that #1 wear ;return number of  #8 for each  #1 ;return #1 where  #9 is equal to  one ;return number of  #1 ;return number of  #10 ;return if  #12 is equal to  #11 ;return if  both  #6 and #13 are true
['select', 'filter', 'filter', 'project', 'project', 'boolean', 'select', 'filter', 'group', 'comparative', 'aggregate', 'aggregate', 'boolean', 'boolean']