Replace Blake2s example with smaller range example

test/range.pir

@@ -0,0 +1,27 @@
+/* Any value 0 <= x < 32 such that the last two bits 1, 0 is valid. For example
+   10 is valid since its bit string is ...1010. Run as follows:
+   vamp-ir setup -o params.pp
+   vamp-ir compile -u params.pp -s tests/range.pir -o circuit.plonk
+   vamp-ir prove -u params.pp -c circuit.plonk -o proof.plonk
+   vamp-ir verify -u params.pp -c circuit.plonk -p proof.plonk
+*/
+
+pub x;
+
+// Ensure that the given argument is 1 or 0, and returns it
+
+def bool x = { x*(x-1) = 0; x };
+
+// Extract 5 bits from a number argument
+
+def bits5 a = {
+    def a0 = bool (fresh ((a\1) % 2));
+    def a1 = bool (fresh ((a\2) % 2));
+    def a2 = bool (fresh ((a\4) % 2));
+    def a3 = bool (fresh ((a\8) % 2));
+    def a4 = bool (fresh ((a\16) % 2));
+    a = a0 + 2*a1 + 4*a2 + 8*a3 + 16*a4;
+    (a0, a1, a2, a3, a4, ())
+};
+
+def x_bits = bits5 x;