Some varieties are crude with lunate sigmas and square omicrons. Its syntax was very close to the usual mathematical notation, using subscripts en sigmas. Yet all Brothers call each other "Sigmas". Sorority, Inc., also known as Sigmas or SYZ, is a progressive multicultural sorority. The efficiency of FIR breaks down for high sigmas. Jack states that all GE products must be "Six Sigmas" to perfection. Sigmas 9s were still in service in 1993. As X approaches the elevator, the doors open, revealing an entire army of Sigmas. The Telefile T-85, introduced in 1979, was an upward compatible drop-in replacement for 32-bit Sigmas. In 2006, seven Sigmas were arrested for beating pledges from the University of South Carolina.