FTYP EQUA 4  ! Sonnet Equation File

EQN "stability factor"
EQS UNKNOWN
EQH 
END EQH 
ARGS 4
ARG 1 ! begin arg 1 definition
NAME S11
ANN S11
RES S 11
END ARG ! end of arg 1 definition
ARG 2 ! begin arg 2 definition
NAME S21
ANN S21
RES S 21
END ARG ! end of arg 2 definition
ARG 3 ! begin arg 3 definition
NAME S12
ANN S12
RES S 12
END ARG ! end of arg 3 definition
ARG 4 ! begin arg 4 definition
NAME S22
ANN S22
RES S 22
END ARG ! end of arg 4 definition
BODY 
(1-(mag(S11))^2-(mag(S22))^2+(mag(S11*S22-S12*S21))^2)/(2*mag(S12*S21))
END BODY 
END EQN