C ELM22A    STORAGE REGISTERS FOR ALGEBRAIC COMBINATIONS OF MATRIX ELEMENTS
C
C REG(20)           VALUES IN REGISTERS
C DREG(20,NPVAR)    PARTIAL DERIVATIVES OF VALUES IN REGISTERS
C LREG(20)          TRUE IF REGISTER HAS VALUE IN IT
C
      LOGICAL         LREG(20)
      REAL            REG(20), DREG(20,NPVAR)
C
      COMMON /ELM22A/ REG, DREG, LREG