diff --git a/20211011/functions-1.c b/20211011/functions-1.c
new file mode 100644
index 0000000000000000000000000000000000000000..181c578ab248af04737711941f21bbf3f0bcc4f2
--- /dev/null
+++ b/20211011/functions-1.c
@@ -0,0 +1,17 @@
+#include <stdio.h>
+
+int answer (void)
+{
+  return 42;
+}
+
+void foo (void)
+{
+  printf ("%d\n", answer ());
+}
+
+int main (void)
+{
+  foo ();
+  return 0;
+}
diff --git a/20211011/functions-10.c b/20211011/functions-10.c
new file mode 100644
index 0000000000000000000000000000000000000000..cf4ed0eef48dae1a89c5dbd7decbdd35d791190c
--- /dev/null
+++ b/20211011/functions-10.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+int a = 0;
+int b = 3;
+
+void foo (void)
+{
+  b++;
+  static int a = 5;
+  int b = 7;
+  printf ("foo(): " "a = %d, b = %d\n", a, b);
+  a++;
+}
+
+int main (void)
+{
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  a = b = 12;
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+
+  return 0;
+
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+}
diff --git a/20211011/functions-11.c b/20211011/functions-11.c
new file mode 100644
index 0000000000000000000000000000000000000000..ffffa799594c7fdb03c9ee957925245338bcee2f
--- /dev/null
+++ b/20211011/functions-11.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+int a = 0;
+int b = 3;
+
+void foo (void)
+{
+  b++;
+  static int a = 5;
+  int b = 7;
+  printf ("foo(): " "a = %d, b = %d\n", a, b);
+  a++;
+}
+
+int main (void)
+{
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  a = b = 12;
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  return 0;
+}
diff --git a/20211011/functions-2.c b/20211011/functions-2.c
new file mode 100644
index 0000000000000000000000000000000000000000..09d985fad681138e9a922a7f21e2379d474604b0
--- /dev/null
+++ b/20211011/functions-2.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+void add_verbose (int a, int b)
+{
+  printf ("%d + %d = %d\n", a, b, a + b);
+}
+
+int main (void)
+{
+  add_verbose (3, 7);
+  return 0;
+}
diff --git a/20211011/functions-3.c b/20211011/functions-3.c
new file mode 100644
index 0000000000000000000000000000000000000000..5b4322f1db9ea2cdda1f6a5c7257c51c2e332879
--- /dev/null
+++ b/20211011/functions-3.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int add_verbose (int a, int b)
+{
+  printf ("%d + %d = %d\n", a, b, a + b);
+  return 42;
+}
+
+int main (void)
+{
+  add_verbose (3, 7);
+  return 0;
+}
diff --git a/20211011/functions-4.c b/20211011/functions-4.c
new file mode 100644
index 0000000000000000000000000000000000000000..66eabf3d8674acd353b3ad377b13869d56fb2499
--- /dev/null
+++ b/20211011/functions-4.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int add_verbose (int a, int b)
+{
+  printf ("%d + %d = %d\n", a, b, a + b);
+  return 42;
+}
+
+int main (void)
+{
+  int a = add_verbose (3, 7);
+  printf ("Rückgabewert: %d\n", a);
+  return 0;
+}
diff --git a/20211011/functions-5.c b/20211011/functions-5.c
new file mode 100644
index 0000000000000000000000000000000000000000..b0a3a5f67e09371531026605e4bbcff672763ce4
--- /dev/null
+++ b/20211011/functions-5.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+void add_verbose (int a, int b)
+{
+  printf ("%d + %d = %d\n", a, b, a + b);
+  return 42;
+}
+
+int main (void)
+{
+  void a = add_verbose (3, 7);
+  printf ("Rückgabewert: %d\n", a);
+  return 0;
+}
diff --git a/20211011/functions-6.c b/20211011/functions-6.c
new file mode 100644
index 0000000000000000000000000000000000000000..354dd538744b944f74aa9de4eacb332c1fdda1ef
--- /dev/null
+++ b/20211011/functions-6.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+
+int a, b = 3;
+
+void foo (void)
+{
+  b++;
+  static int a = 5;
+  int b = 7;
+  printf ("foo(): " "a = %d, b = %d\n", a, b);
+  a++;
+}
+
+int main (void)
+{
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+
+  return 0;
+
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  a = b = 12;
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+}
diff --git a/20211011/functions-7.c b/20211011/functions-7.c
new file mode 100644
index 0000000000000000000000000000000000000000..1d89a24d9b1f516eba8b5a6cc8a27efc4f75c4f5
--- /dev/null
+++ b/20211011/functions-7.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+int a = 0;
+int b = 3;
+
+void foo (void)
+{
+  b++;
+  static int a = 5;
+  int b = 7;
+  printf ("foo(): " "a = %d, b = %d\n", a, b);
+  a++;
+}
+
+int main (void)
+{
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+
+  return 0;
+
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  a = b = 12;
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+}
diff --git a/20211011/functions-8.c b/20211011/functions-8.c
new file mode 100644
index 0000000000000000000000000000000000000000..2e18b511c9adf0eab46456a94ff76cb8bea05e73
--- /dev/null
+++ b/20211011/functions-8.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+int a = 0;
+int b = 3;
+
+void foo (void)
+{
+  b++;
+  static int a = 5;
+  int b = 7;
+  printf ("foo(): " "a = %d, b = %d\n", a, b);
+  a++;
+}
+
+int main (void)
+{
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+
+  return 0;
+
+  a = b = 12;
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+}
diff --git a/20211011/functions-9.c b/20211011/functions-9.c
new file mode 100644
index 0000000000000000000000000000000000000000..73a3ab636343d59bf21827668c5124b28dff1d25
--- /dev/null
+++ b/20211011/functions-9.c
@@ -0,0 +1,27 @@
+#include <stdio.h>
+
+int a = 0;
+int b = 3;
+
+void foo (void)
+{
+  b++;
+  static int a = 5;
+  int b = 7;
+  printf ("foo(): " "a = %d, b = %d\n", a, b);
+  a++;
+}
+
+int main (void)
+{
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+  a = b = 12;
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+
+  return 0;
+
+  foo ();
+  printf ("main(): " "a = %d, b = %d\n", a, b);
+}
diff --git a/20211011/hp-20211011.pdf b/20211011/hp-20211011.pdf
index ef596911793de3d62b3aaddab01464fb7517cf30..29fce7a42e97d44fe6867372ec13a2cbae8f3449 100644
Binary files a/20211011/hp-20211011.pdf and b/20211011/hp-20211011.pdf differ
diff --git a/20211011/hp-20211011.tex b/20211011/hp-20211011.tex
index 76ff44ed015c930207de2f3694aea10627e337b5..535b15bf177efbec914b9cdb76e88f85feff4883 100644
--- a/20211011/hp-20211011.tex
+++ b/20211011/hp-20211011.tex
@@ -437,7 +437,8 @@
         Apple Mac OS: \file{Xcode}
       \item
         Microsoft Windows: \file{Cygwin}\\
-        oder \file{MinGW} mit \file{MSYS}
+        oder \file{MinGW} mit \file{MSYS}\\
+        oder \file{WSL} mit \file{Xming}
       \medskip
       \item
         außerdem: Texteditor\\
diff --git a/20211011/pointers-1.c b/20211011/pointers-1.c
new file mode 100644
index 0000000000000000000000000000000000000000..421153a64907b61eebbacec398ed4f1fcb487cc6
--- /dev/null
+++ b/20211011/pointers-1.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+void calc_answer (int a)
+{
+  a = 42;
+}
+
+int main (void)
+{
+  int answer;
+  calc_answer (answer);
+  printf ("The answer is %d.\n", answer);
+  return 0;
+}
diff --git a/20211011/pointers-2.c b/20211011/pointers-2.c
new file mode 100644
index 0000000000000000000000000000000000000000..3bd2e86c08fbe05eb8eb9b42d886e30f8f0be286
--- /dev/null
+++ b/20211011/pointers-2.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+void calc_answer (int *a)
+{
+  *a = 42;
+}
+
+int main (void)
+{
+  int answer;
+  calc_answer (&answer);
+  printf ("The answer is %d.\n", answer);
+  return 0;
+}
diff --git a/20211011/pointers-3-O0.s b/20211011/pointers-3-O0.s
new file mode 100644
index 0000000000000000000000000000000000000000..6a28ff560ab4123895be3a93b419836c7c23eef2
--- /dev/null
+++ b/20211011/pointers-3-O0.s
@@ -0,0 +1,55 @@
+	.file	"pointers-3.c"
+	.text
+	.globl	calc_answer
+	.type	calc_answer, @function
+calc_answer:
+.LFB0:
+	.cfi_startproc
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	movq	%rdi, -8(%rbp)
+	movq	-8(%rbp), %rax
+	movl	$42, (%rax)
+	nop
+	popq	%rbp
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+.LFE0:
+	.size	calc_answer, .-calc_answer
+	.section	.rodata
+.LC0:
+	.string	"The answer is %d.\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB1:
+	.cfi_startproc
+	pushq	%rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset 6, -16
+	movq	%rsp, %rbp
+	.cfi_def_cfa_register 6
+	subq	$16, %rsp
+	movl	-4(%rbp), %eax
+	cltq
+	movq	%rax, %rdi
+	call	calc_answer
+	movl	-4(%rbp), %eax
+	movl	%eax, %esi
+	leaq	.LC0(%rip), %rdi
+	movl	$0, %eax
+	call	printf@PLT
+	movl	$0, %eax
+	leave
+	.cfi_def_cfa 7, 8
+	ret
+	.cfi_endproc
+.LFE1:
+	.size	main, .-main
+	.ident	"GCC: (Debian 8.3.0-6) 8.3.0"
+	.section	.note.GNU-stack,"",@progbits
diff --git a/20211011/pointers-3-O1.s b/20211011/pointers-3-O1.s
new file mode 100644
index 0000000000000000000000000000000000000000..c03481f3891c2a8f2be7e898f96ff6669c322890
--- /dev/null
+++ b/20211011/pointers-3-O1.s
@@ -0,0 +1,36 @@
+	.file	"pointers-3.c"
+	.text
+	.globl	calc_answer
+	.type	calc_answer, @function
+calc_answer:
+.LFB11:
+	.cfi_startproc
+	movl	$42, (%rdi)
+	ret
+	.cfi_endproc
+.LFE11:
+	.size	calc_answer, .-calc_answer
+	.section	.rodata.str1.1,"aMS",@progbits,1
+.LC0:
+	.string	"The answer is %d.\n"
+	.text
+	.globl	main
+	.type	main, @function
+main:
+.LFB12:
+	.cfi_startproc
+	subq	$8, %rsp
+	.cfi_def_cfa_offset 16
+	movl	$0, %esi
+	leaq	.LC0(%rip), %rdi
+	movl	$0, %eax
+	call	printf@PLT
+	movl	$0, %eax
+	addq	$8, %rsp
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+.LFE12:
+	.size	main, .-main
+	.ident	"GCC: (Debian 8.3.0-6) 8.3.0"
+	.section	.note.GNU-stack,"",@progbits
diff --git a/20211011/pointers-3.c b/20211011/pointers-3.c
new file mode 100644
index 0000000000000000000000000000000000000000..7867933ea67073e239e5b307d2c219639442be77
--- /dev/null
+++ b/20211011/pointers-3.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+void calc_answer (int *a)
+{
+  *a = 42;
+}
+
+int main (void)
+{
+  int answer;
+  calc_answer (answer);
+  printf ("The answer is %d.\n", answer);
+  return 0;
+}
diff --git a/20211011/side-effects-1.c b/20211011/side-effects-1.c
new file mode 100644
index 0000000000000000000000000000000000000000..61c4abb82e369b17b5acc83107b9baa598f371d2
--- /dev/null
+++ b/20211011/side-effects-1.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  "Hello, world!\n";
+  return 0;
+}
diff --git a/20211011/side-effects-10.c b/20211011/side-effects-10.c
new file mode 100644
index 0000000000000000000000000000000000000000..a8b7d83fa59ff7c170192dd330125b39297ba071
--- /dev/null
+++ b/20211011/side-effects-10.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159;
+  printf ("pi = %lf\n", pi);
+  return 0;
+}
diff --git a/20211011/side-effects-11.c b/20211011/side-effects-11.c
new file mode 100644
index 0000000000000000000000000000000000000000..ec7fb456f4f3e7e6fbde8402fe5f5608a9259c72
--- /dev/null
+++ b/20211011/side-effects-11.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3, po = 14159;
+  printf ("pi = %lf, po = %lf\n", pi, po);
+  return 0;
+}
diff --git a/20211011/side-effects-12.c b/20211011/side-effects-12.c
new file mode 100644
index 0000000000000000000000000000000000000000..9ebbaa2f296153bb8d960b6c82009418ccdb9e64
--- /dev/null
+++ b/20211011/side-effects-12.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = (3,14159);
+  printf ("pi = %lf\n", pi);
+  return 0;
+}
diff --git a/20211011/side-effects-13.c b/20211011/side-effects-13.c
new file mode 100644
index 0000000000000000000000000000000000000000..b6d4b13142282353973962d43f3c52cf2a6ee27d
--- /dev/null
+++ b/20211011/side-effects-13.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  double x = pi;
+  for (int i = 1; i <= 10; i++)
+    {
+      printf ("%2d: %lf\n", x);
+      x += pi;
+    }
+  return 0;
+}
diff --git a/20211011/side-effects-14.c b/20211011/side-effects-14.c
new file mode 100644
index 0000000000000000000000000000000000000000..6b14797d23ba1737a85b93e06cd7d143922515fd
--- /dev/null
+++ b/20211011/side-effects-14.c
@@ -0,0 +1,15 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  double x = pi;
+  for (int i = 1; i <= 10; i++)
+    {
+      printf ("%2d: %lf\n", i, x);
+      x += pi;
+    }
+  return 0;
+}
diff --git a/20211011/side-effects-15.c b/20211011/side-effects-15.c
new file mode 100644
index 0000000000000000000000000000000000000000..ea4a227909eb28c1f4d2d207caa23c8cca1c8f92
--- /dev/null
+++ b/20211011/side-effects-15.c
@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  double x;
+  for (int i = 1, x = pi; i <= 10; i++, x += pi)
+    printf ("%2d: %lf\n", i, x);
+  return 0;
+}
diff --git a/20211011/side-effects-16.c b/20211011/side-effects-16.c
new file mode 100644
index 0000000000000000000000000000000000000000..86570b8dc03ae1f5d0bf48b6171f5e8aed83da6c
--- /dev/null
+++ b/20211011/side-effects-16.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  int i;
+  double x;
+  for (i = 1, x = pi; i <= 10; i++, x += pi)
+    printf ("%2d: %lf\n", i, x);
+  return 0;
+}
diff --git a/20211011/side-effects-17.c b/20211011/side-effects-17.c
new file mode 100644
index 0000000000000000000000000000000000000000..ab2fae4b23ba978e429df9ec7fe79c972f5a261c
--- /dev/null
+++ b/20211011/side-effects-17.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  int i = 1;
+  double x = pi;
+  for (; i <= 10; i++, x += pi)
+    printf ("%2d: %lf\n", i, x);
+  return 0;
+}
diff --git a/20211011/side-effects-18.c b/20211011/side-effects-18.c
new file mode 100644
index 0000000000000000000000000000000000000000..62c8cd1599c54c689826fd8fb167c1ec54c83f1b
--- /dev/null
+++ b/20211011/side-effects-18.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  int i = 1;
+  double x = pi;
+  for (; i <= 10; x += pi)
+    printf ("%4d: %lf\n", i++, x);
+  return 0;
+}
diff --git a/20211011/side-effects-19.c b/20211011/side-effects-19.c
new file mode 100644
index 0000000000000000000000000000000000000000..d2a8706fb288f913138cfbac4e99573835e04bdf
--- /dev/null
+++ b/20211011/side-effects-19.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  int i = 1;
+  double x = 0.0;
+  for (; i <= 10;)
+    printf ("%4d: %lf\n", i++, x += pi);
+  return 0;
+}
diff --git a/20211011/side-effects-2.c b/20211011/side-effects-2.c
new file mode 100644
index 0000000000000000000000000000000000000000..275a28e55e4568ff0e7f135bfaae8de819d224f7
--- /dev/null
+++ b/20211011/side-effects-2.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  42;
+  return 0;
+}
diff --git a/20211011/side-effects-20.c b/20211011/side-effects-20.c
new file mode 100644
index 0000000000000000000000000000000000000000..7b1ff964f3d7461cba8b2e322d43f1227e2c1896
--- /dev/null
+++ b/20211011/side-effects-20.c
@@ -0,0 +1,13 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3.14159265358979323846;
+  printf ("pi = %lf\n", pi);
+  printf ("Vielfache von pi:\n");
+  int i = 1;
+  double x = 0.0;
+  while (i <= 10)
+    printf ("%4d: %lf\n", i++, x += pi);
+  return 0;
+}
diff --git a/20211011/side-effects-3.c b/20211011/side-effects-3.c
new file mode 100644
index 0000000000000000000000000000000000000000..38c183ed039e62071e61c0b6b62b46bd5341dfd8
--- /dev/null
+++ b/20211011/side-effects-3.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  printf ("Hello, world!\n");
+  int a = 42;
+  return 0;
+}
diff --git a/20211011/side-effects-4.c b/20211011/side-effects-4.c
new file mode 100644
index 0000000000000000000000000000000000000000..e316c749c4c730c36613ebd558ccfb7687f0b9d3
--- /dev/null
+++ b/20211011/side-effects-4.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  int a = printf ("Hello, world!\n");
+  printf ("Die Antwort lautet: %d\n", a);
+  return 0;
+}
diff --git a/20211011/side-effects-5.c b/20211011/side-effects-5.c
new file mode 100644
index 0000000000000000000000000000000000000000..aef0a3dea163f1ea7f5f4922c9d451403671ec25
--- /dev/null
+++ b/20211011/side-effects-5.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main (void)
+{
+  int a = 137;
+  int b = a = 42;
+  printf ("Die Antwort lautet: %d\n", a);
+  printf ("Die Bntwort lautet: %d\n", b);
+  return 0;
+}
diff --git a/20211011/side-effects-6.c b/20211011/side-effects-6.c
new file mode 100644
index 0000000000000000000000000000000000000000..be6f48e98e7934cc487e35dd8b797535c6f6e0ab
--- /dev/null
+++ b/20211011/side-effects-6.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main (void)
+{
+  int a = 137;
+  int b = a += 42;
+  printf ("Die Antwort lautet: %d\n", a);
+  printf ("Die Bntwort lautet: %d\n", b);
+  return 0;
+}
diff --git a/20211011/side-effects-7.c b/20211011/side-effects-7.c
new file mode 100644
index 0000000000000000000000000000000000000000..bd9fe634ed2b0048f76f9a75b328664508df9a1a
--- /dev/null
+++ b/20211011/side-effects-7.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main (void)
+{
+  int a = 137;
+  int b = a++;
+  printf ("Die Antwort lautet: %d\n", a);
+  printf ("Die Bntwort lautet: %d\n", b);
+  return 0;
+}
diff --git a/20211011/side-effects-8.c b/20211011/side-effects-8.c
new file mode 100644
index 0000000000000000000000000000000000000000..b3643052e1c10d1478c4b5f4db2e431a64af9579
--- /dev/null
+++ b/20211011/side-effects-8.c
@@ -0,0 +1,10 @@
+#include <stdio.h>
+
+int main (void)
+{
+  int a = 137;
+  int b = ++a;
+  printf ("Die Antwort lautet: %d\n", a);
+  printf ("Die Bntwort lautet: %d\n", b);
+  return 0;
+}
diff --git a/20211011/side-effects-9.c b/20211011/side-effects-9.c
new file mode 100644
index 0000000000000000000000000000000000000000..effe4f62347f00a84c7e08f61c9a1172d62cf558
--- /dev/null
+++ b/20211011/side-effects-9.c
@@ -0,0 +1,8 @@
+#include <stdio.h>
+
+int main (void)
+{
+  double pi = 3,14159;
+  printf ("pi = %lf\n", pi);
+  return 0;
+}