## APPENDIX A 

## Predeclared Procedures and Functions 

## Abs (x) 

an arithmetic function that computes I ~Ie real absolute value of a real parameter x or the integer absolute value of an integel parameter x. 

## ArcTan (x) 

an arithmetic function that computes the real arctangent (principal value) in ra­ dians of a real or integer parameter x. 

## Chr(i) 

a transfer function that returns the chi' racter whose ordinal number is the integer parameter i. Ch r ( i ) is an error if such a character value does not exist. 

## Dispose (q) 

a dynamic-allocation procedure that d .:allocates an identified variable q i and de­ stroystheidentifyingvalueq. Dispose (1) isanerrorifq isnil orundefmed. The value q must have been created by II K~ short form of New. 

## Dispose(q,kl, ... ,kn) 

a dynamic-allocation procedure that aeallocates an identified record variable q i and destroys the identifying value q. DisF ose (q, kl, ... , kn) is an error if q is nil or undefined. The value q must have been created by the long form of New and kl, ... , kn must select the same variants selected when q was created. 

## Eof (f) 

a Boolean function that returns t ru ~ if the file variable f is in generation mode, or if f is positioned past the last COl Iponent in its sequence and f is in inspec­ tion mode. eof (f) is anerrorif f is un! cfined. Otherwise eof (f) returns false. If f is omitted, program parameter Inpl t. is assumed. 

## Eoln (f) 

a Boolean function that returns true 1 f the textfile f, when in inspection mode, is positioned at an end-of-line marker. e( .. n (f) is an error if f is undefined or if eof (f) is true. Otherwise eoln (f) I .:tums false. If f is omitted, program pa­ rameter Input is assumed. 

