 [det]read_file_to_terms(+Spec, 
-Terms, +Options)
[det]read_file_to_terms(+Spec, 
-Terms, +Options)\Tail forms a difference 
list.
Note that the output options of read_term/3, 
such as
variable_names or subterm_positions will cause
read_file_to_terms/3 
to fail if Spec contains multiple terms because the values 
for the different terms will not unify.