Spec now says std.makeArray(0, null) and std.filter(null, []) are err…

…ors.

doc/language/spec.html

@@ -1606,14 +1606,18 @@ <h4 id="execution">Execution</h4>
 
 <div class="sequent-rule"> \[\rule{makeArray} {
 e ↓ n
+\\
+e' ↓ f ∈ Function
 } {
-\texttt{std.makeArray}(e, e') ↓ \array{e'(0) \ldots e'(n - 1)}
+\texttt{std.makeArray}(e, e') ↓ \array{f(0) \ldots f(n - 1)}
 } \] </div>
 
 <div class="sequent-rule"> \[\rule{filter} {
+e ↓ f ∈ Function
+\\
 e' ↓ \array{e_0 \ldots e_{n - 1}}
 \\
-j_1 \ldots j_m = \{ i \ |\  e(e_i) ↓ \true \}
+j_1 \ldots j_m = \{ i \ |\  f(e_i) ↓ \true \}
 } {
 \texttt{std.filter}(e, e') ↓ \array{e_{j_1} \ldots e_{j_m}}
 } \] </div>