Therefore it is rarely the case that Leray 's result is quoted in its original form .
At the time of Leray 's work , neither of the two concepts involved ( spectral sequence , sheaf cohomology ) had reached anything like a definitive state .
It is rarely the case that Leray 's result is quoted in its original form .
At the time of Leray 's work , neither of the two concepts involved ( spectral sequence , sheaf cohomology ) had reached anything like a definitive state .