The four NAND gates of a 4011 are used in the clocked R-S flip-flop shown here. The circuit is set and reset by positive pulses in the inputs, and these pulses pass when the clock input is high. If the inputs remain open at moments during the operation, a 100 k ohm resistor to ground is needed. Other NAND gates can be used in the same configuration as the ones found in a 4093.
Clocked R-S Flip Flop