question: If the top shell of a crab is visible in each image, and the crabs on the left and right are displayed in the same position and manner.
#1 return crab 
#2 return top shell of #1 
#3 return #2 that is visible 
#4 return images of #3 
#5 return images 
#6 return number of  #4 
#7 return number of  #5 
#8 return if  #6 is equal to  #7 
#9 return #1 on the  left 
#10 return #1 on the  right 
#11 return position displayed in  of #9 
#12 return position displayed in  of #10 
#13 return if  #11 is the  same as #12 
#14 return manner displayed in  of #9 
#15 return manner displayed in  of #10 
#16 return if  #14 is the  same as #15 
#17 return if  both  #13 and   #16 are true 
#18 return if  both  #8 and   #17 are true