I need to finish this code in Fortran, the code calculates the inverse matrix of a $4$x$4$ matrix that reads from the data.dat file, this can be anything. I need to implement the two subroutines that are there $($triangulars and triangulari$),$ one is to triangulate superiorly and the other inferiorly. And finally check that the code is correct by compiling it$.$

That is$,$ it is the base code, I don't know if it is necessary to add something else for it to work. program inverse$\_$calculation

real :: a$(1$:$100,1$:$200),$b$(1$:$100,1$:$100),$c$(1$:$100,1$:$100)$

open$($unit$=10,$file$=$'data.dat'$)$

n$=4$

do i$=1,$n

read$(10,*)($a$($i$,$j$),$ j$=1,$n$)$

enddo

close$(10)$

a$(1$:n$,$n$+1$:$2*$n$)=0\mathrm{.}0$

do i$=1,$n

a$($i$,$n$+$i$)=1\mathrm{.}0$

enddo

call triangulars$($a$(1$:n$,1$:$2*$n$),$n$)$

call triangulari$($a$(1$:n$,1$:$2*$n$),$n$)$

do i$=1,$n

a$($i$,$:$)=$a$($i$,$:$)/$a$($i$,$i$)$

enddo

do i$=1,$n

write$(*,*)($a$($i$,$j$),$ j$=1,$n$)$

enddo

write$(*,*)\text{'}**********************************\text{'}$

do i$=1,$n

write$(*,*)($a$($i$,$j$),$ j$=$n$+1,2*$n$)$

enddo

open$($unit$=12,$file$=$'data.dat'$)$

do i$=1,$n

read$(12,*)($b$($i$,$j$),$ j$=1,$n$)$

enddo

write$(*,*)\text{'}***********************************\text{'}$

do i$=1,$n

write$(*,*)($b$($i$,$j$),$ j$=1,$n$)$

enddo

close$(12)$

$!$ Verification of the inverse calculation procedure

do i$=1,$n

do j$=1,$n

c$($i$,$j$)=$dot$\_$product$($a$($i$,$n$+1$:$2*$n$),$b$($:$,$j$))$

enddo

enddo

write$(*,*)\text{'}*************************************\text{'}$

do i$=1,$n

write$(*,*)($c$($i$,$j$),$ j$=1,$n$)$

enddo

end