abaqus UMAT二次开发能用fortran90吗？

       SUBROUTINE UMAT(STRESS,STATEV,DDSDDE,SSE,SPD,SCD,RPL,DDSDDT,
      # DRPLDE,DRPLDT,STRAN,DSTRAN,TIME,DTIME,TEMP,DTEMP,PREDEF,DPRED,
      # CMNAME,NDI,NSHR,NTENS,NSTATEV,PROPS,NPROPS,COORDS,DROT,PNEWDT,
      # CELENT,DFGRD0,DFGRD1,NOEL,NPT,LAYER,KSPT,KSTEP,KINC)
       INCLUDE 'ABA_PARAM.INC'
       CHARACTER() CMNAME
       REAL() STRESS(NTENS),STATEV(NSTATEV),DDSDDE(NTENS,NTENS),
      # DDSDDT(NTENS),DRPLDE(NTENS),STRAN(NTENS),DSTRAN(NTENS),TIME(),
      # PREDEF(),DPRED(),PROPS(NPROPS),COORDS(),DROT(,),
      # DFGRD0(,),DFGRD1(,)
       REAL() rE !杨氏模量
       REAL() rMu !泊松比
       REAL() rG !剪切模量
       REAL() rLambda !拉梅常数
       rE= -0.4 * ( 0.5*COORDS()**+3.0*COORDS()** ) +
       rMu= 0.25
       rG=rE/(2.0*(1.0+rMu))
       rLambda=(2.0*rMu*rG)/(1.0-2.0*rMu)
       DO i=,NTENS,
         DO j=,NTENS,
             DDSDDE(i,j)=0.0
         END DO
       END DO
       DO i=,NDI,
         DO j=,NDI,
             DDSDDE(i,j)=rLambda
         END DO
             DDSDDE(i,i)=rLambda+2.0*rG
       END DO
       DO i=NDI+,NTENS,
         DDSDDE(i,i)=rG
       END DO
       DO i=,NTENS,
         DO j=,NTENS,
             STRESS(i)=STRESS(i)+DDSDDE(i,j)*DSTRAN(j)
         END DO
       END DO
       DO i=,NTENS,
         STRAN(i)=STRAN(i)+DSTRAN(i)
       END DO
       SSE=
       DO i=,NTENS,
         SSE=SSE+STRESS(i)*STRAN(i)
       END DO
       SSE=0.5*SSE
       STATEV()=rE
       RETURN
       END SUBROUTINE UMAT

这个例题好奇怪，里面是f90的语法，文档名后缀却是.for。