Techniques and systems are described for improving the efficiency of timing calculations in numerical sequential cell sizing and for improving the efficiency of incremental slack margin propagation. or lower; the ink exhibits the characteristic of being jetted without purging from a printer maintained at a standby temperature of about 100\xb0 C. The fullerene may be C60 or C70. A pin seal device is located in one of the connector units and has a through bore which engages part of the pin at least in the mated condition of the units. The lens fastener pushes the circumferential part of the optical lens, thereby to deform the elastic member to adjust the position of a focal point of the optical lens. Such resistive materials having a resistivity in a first direction and a very different resistivity in an orthogonal direction.