! Structura:
! f(i) = expresie; i =1,n;
subroutine fcn(n, w, f)
dimension w(n),f(n)

f =0.
x =w(1)
y =w(2)
if(n >=3) z =w(3)

! Ex. curs:
!f(1) =x*x+ y*y -5.
!f(2) =y -exp(x) -1.



! Vahidi 2012:(0.5,0,-pi/6)
!x1 =w(1); x2 =w(2); x3 =w(3);
!pi =2*asin(1.)
!f(1) =3*x1 -cos(x2*x3)- 1/2. 
!f(2) =x1*x1 -81*(x2 + 0.1)**2 +sin(x3) + 1.06
!f(3) =exp(-x1*x2) + 20*x3 + (10*pi-3)/3

end


