EX 2.9 operations on events of EX 2.4

(EX 2.4 infinitely many outputs continued) In the program compilation experiment, define $A,B$ , and $C$ by

• $A=\{S,FS,FFS\}$
• $B=\{S,FFS,FFFFS\}$
• $C=\{FS,FFFS,FFFFFS,\dots \}$

Then

• $A^{\prime }=\{FFFS,FFFFS,FFFFFS,\dots \}$
• $C^{\prime }=\{S,FFS,FFFFS,\dots \}$
• $A\cup B=\{S,FS,FFS,FFFFS\}$
• $A\cap B=\{S,FFS\}$