De Rham–Weil theorem
In algebraic topology, the De Rham–Weil theorem allows computation of sheaf cohomology using an acyclic resolution of the sheaf in question. Let formula_1 be a sheaf on a topological space formula_2 and formula_3 a resolution of formula_1 by acyclic sheaves. Then where formula_6 denotes the formula_7-th sheaf cohomology group of formula_2 with coefficients in formula_9 The De Rham–Weil theorem follows from the more general fact that derived functors may be computed using acyclic resolutions instead of simply injective resolutions.