===== Non-negative real number ===== ==== Set ==== | @#FFBB00: definiendum | @#FFBB00: $ r \in\mathbb R_+ $ | | @#55EE55: postulate | @#55EE55: $ r \ge 0 $ | ==== Discussion ==== ==== Reference ==== Wikipedia: [[http://en.wikipedia.org/wiki/Real_number|Real number]] ==== Parents ==== === Subset of === [[Real number]]