diff --git a/notes/3.md b/notes/3.md
index ebe8130..9d53785 100644
--- a/notes/3.md
+++ b/notes/3.md
@@ -52,7 +52,7 @@ void sumstore(long x, long y, long *dest) {
 ```
 
 ```sh {cmd hide}
-while ! [ -r 3_1.o ]; do sleep .1; done; objdump -d 3_1.o
+while ![ -r 3_1.o ]; do sleep .1; done; objdump -d 3_1.o
 ```
 
 ### Integer Registers
@@ -267,7 +267,7 @@ long absdiff(long x, long y) {
 ```
 
 ```sh { cmd hide }
-while ! [ -r 3_3.o ]; do sleep .1; done; objdump -d 3_3.o -Msuffix
+while ![ -r 3_3.o ]; do sleep .1; done; objdump -d 3_3.o -Msuffix
 ```
 
 **expressing with `goto`**
@@ -300,7 +300,7 @@ long absdiff(long x, long y) {
 ```
 
 ```sh {cmd hide}
-while ! [ -r 3_5.o ]; do sleep .1; done; objdump -d 3_5.o -Msuffix
+while ![ -r 3_5.o ]; do sleep .1; done; objdump -d 3_5.o -Msuffix
 ```
 
 However, there are several *bad cases* for conditional move.
@@ -357,7 +357,7 @@ loop:
 </table>
 
 ```sh {cmd hide}
-while ! [ -r 3_6.o ]; do sleep .1; done; objdump -d 3_6.o -Msuffix
+while ![ -r 3_6.o ]; do sleep .1; done; objdump -d 3_6.o -Msuffix
 ```
 
 **general do-while translation**
@@ -426,7 +426,7 @@ long pcount_while(unsigned long x) {
 ```
 ```sh {cmd hide}
 echo "jmp-to-middle translation"
-while ! [ -r 3_7.o ]; do sleep .1; done; objdump -d 3_7.o -Msuffix
+while ![ -r 3_7.o ]; do sleep .1; done; objdump -d 3_7.o -Msuffix
 ```
 
 **general while translation#2**
@@ -478,7 +478,7 @@ long pcount_while(unsigned long x) {
 ```
 ```sh {cmd hide}
 echo "while to do-while conversion"
-while ! [ -r 3_8.o ]; do sleep .1; done; objdump -d 3_8.o -Msuffix
+while ![ -r 3_8.o ]; do sleep .1; done; objdump -d 3_8.o -Msuffix
 ```
 
 #### for loop form
@@ -560,13 +560,13 @@ long pcount_for(unsigned long x) {
 <td>
 
 ```sh {cmd hide}
-while ! [ -r 3_9.o ]; do sleep .1; done; objdump -d 3_9.o -Msuffix
+while ![ -r 3_9.o ]; do sleep .1; done; objdump -d 3_9.o -Msuffix
 ```
 </td>
 <td>
 
 ```sh {cmd hide}
-while ! [ -r 3_10.o ]; do sleep .1; done; objdump -d 3_10.o -Msuffix
+while ![ -r 3_10.o ]; do sleep .1; done; objdump -d 3_10.o -Msuffix
 ```
 </td>
 </tr>
@@ -614,7 +614,7 @@ long switch_eg (long x, long y, long z) {
 <td>
 
 ```sh {cmd hide}
-while ! [ -r 3_11.s ]; do sleep .1; done; cat 3_11.s
+while ![ -r 3_11.s ]; do sleep .1; done; cat 3_11.s
 ```
 </td>
 </tr>
@@ -667,7 +667,7 @@ void multstore(long x, long y, long *dest) {
 ```
 
 ```sh {cmd hide}
-while ! [ -r 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
+while ![ -r 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
 ```
 
 Procedure call `call label`
@@ -687,7 +687,7 @@ Procedure return: `ret`
 for example with above example
 
 ```sh {cmd hide}
-while ! [ -r 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
+while ![ -r 3_12.o ]; do sleep .1; done; objdump -d 3_12.o -Msuffix
 ```
 
 * with above `mult2` variable `t` is already stored in `%rax`
@@ -735,5 +735,5 @@ long call_incr() {
 ```
 
 ```sh {cmd hide}
-while ! [ -r 3_13.o ]; do sleep .1; done; objdump -d 3_13.o -Msuffix
+while ![ -r 3_13.o ]; do sleep .1; done; objdump -d 3_13.o -Msuffix
 ```
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