added and tree

test/unit_tests/andtree_5/test.prsim

@@ -0,0 +1,50 @@
+watchall
+
+system "echo '0'"
+
+set t.in[0] 0
+set t.in[1] 0
+set t.in[2] 0
+set t.in[3] 0
+set t.in[4] 0
+
+system "echo '1'"
+
+cycle
+mode run
+
+assert t.out 0
+
+system "echo '[] setting some bits high'"
+set t.in[0] 1
+set t.in[1] 1
+set t.in[2] 1
+
+cycle
+
+assert t.out 0
+
+system "echo '[] setting all bits high'"
+set t.in[3] 1
+set t.in[4] 1
+
+cycle
+assert t.out 1
+
+
+system "echo '[] setting some low'"
+set t.in[0] 0
+set t.in[1] 0
+
+cycle 
+assert t.out 0
+
+
+system "echo '[] setting all low'"
+set t.in[2] 0
+set t.in[3] 0
+set t.in[4] 0
+
+cycle 
+assert t.out 0
+