Finished Chapter 4

2026-03-10 13:05:37 +01:00
parent 059f9724c4
commit 61da31dcdc
5 changed files with 364 additions and 0 deletions
--- a/chap_3/e3_2.dfy
+++ b/chap_3/e3_2.dfy
@@ -0,0 +1,17 @@
+function M(x: int, b: bool): int 
+    decreases !b
+{
+    if b then x else M(x + 25, true) 
+}
+
+function N(x: int, y: int, b: bool): int 
+    decreases x, b
+{
+    if x <= 0 || y <= 0 then
+        x + y
+    else if b then
+        N(x, y + 3, !b)
+    else
+        N(x - 1, y, true)
+}
+