The system $$\mathop X\limits^ \bullet = AX + BU$$ with $$A = \left[ {\matrix{ { - 1} & 2 \cr 0 & 2 \cr } } \right],$$ $$B = \left[ {\matrix{ 0 \cr 1 \cr } } \right]$$ is

A minimized form of the function $$F$$ is

Which of the following circuits is a realization of the previous function $$F$$ $$?$$

The $$TTL$$ circuit shown in the figure is fed with the waveform $$X$$ (also shown). All gates have equal propagation delay of $$10$$ $$ns.$$ The output $$Y$$ of the circuit is