The 4007 integrated circuit contains three complementary enhancement-mode MOSFET pairs. One pair has connections to the drain terminals, one to the source terminals and the commoned drains (i.e. it is wired as an inverter) and one allows access to all source and drain connections. All pairs have the gate terminals commoned and available. The bulk connections are to the power rails (VDD for the p-channel devices and VSS for the n-channel devices).
The meanings of the abbreviations on the diagrams to the right are:
Pins
Functions
SP2, SP3
Source terminals of 2nd and 3rd p-channel MOSFETs
DP1, DP2
Drain terminals of 1st and 2nd p-channel MOSFETs
DN1, DN2
Drain terminals of 1st and 2nd n-channel MOSFETs
SN2, SN3
Source terminals of 2nd and 3rd n-channel MOSFETs
D3
Drain terminals (common) of 3rd p-channel and n-channel MOSFETs