| 
421
 | 
     1  | 
import M3._
  | 
390
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     2  | 
  | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     3  | 
assert(nullable(ZERO) == false)
  | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     4  | 
assert(nullable(ONE) == true)
  | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     5  | 
assert(nullable(CHAR('a')) == false)
 | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     6  | 
assert(nullable(ZERO | ONE) == true)
  | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     7  | 
assert(nullable(ZERO | CHAR('a')) == false)
 | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     8  | 
assert(nullable(ONE ~  ONE) == true)
  | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
     9  | 
assert(nullable(ONE ~ CHAR('a')) == false)
 | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
    10  | 
assert(nullable(STAR(ZERO)) == true)
  | 
Christian Urban <christian.urban@kcl.ac.uk> 
parents:  
diff
changeset
 
 | 
    11  | 
  |