tiStride = 1
tiStride =-1
tIlo = tIlo-tiStride*(eWdth-1)
tIhi = tIhi+tiStride*(eWdth-1)
tIlo = tIlo+tiStride
tIhi = tIhi-tiStride
O tiStride, tjStride,
INTEGER tiStride, tjStride
tIlo1 = tIlo-tiStride*(eWdth-1)
tIhi1 = tIhi+tiStride*(eWdth-1)
tIlo1 = tIlo+tiStride
tIhi1 = tIhi-tiStride