problem with library function

i use fortran library for solving system of nonlinear equations . (i
use NEQNF) .
i want this program computes some numbers and subsitute them in
nonlinear equations then solve system .
my problem is equations of system must be defined in subroutines ,and
in subroutines it can't be understand the values that computed in main
program !
when fortran starts debuging subroutine ,it thinks these variables
are not defined before and take their values zero !
can anybody helps me ?
best,nakisa

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