small fix

doc/src/manual/mathematical-operations.md

@@ -179,7 +179,7 @@ all vectorized "dot calls," these "dot operators" are
 *fusing*. For example, if you compute `2 .* A.^2 .+ sin.(A)` (or
 equivalently `@. 2A^2 + sin(A)`, using the [`@.`](@ref @__dot__) macro) for
 an array `A`, it performs a *single* loop over `A`, computing `2a^2 + sin(a)`
-for each element of `A`. In particular, nested dot calls like `f.(g.(x))`
+for each element `a` of `A`. In particular, nested dot calls like `f.(g.(x))`
 are fused, and "adjacent" binary operators like `x .+ 3 .* x.^2` are
 equivalent to nested dot calls `(+).(x, (*).(3, (^).(x, 2)))`.