| agc | Number of atom garbage collections 
performed | 
| agc_gained | Number of atoms removed | 
| agc_time | Time spent in atom garbage 
collections | 
| atoms | Total number of defined atoms | 
| c_stack | System (C-) stack limit. 0 if not 
known. | 
| cgc | Number of clause garbage collections 
performed | 
| cgc_gained | Number of clauses reclaimed | 
| cgc_time | Time spent in clause garbage 
collections | 
| clauses | Total number of clauses in the 
program | 
| codes | Total size of (virtual) executable 
code in words | 
| cputime | (User) CPU 
time since thread was started in seconds | 
| epoch | Time stamp when thread was started | 
| functors | Total number of defined name/arity 
pairs | 
| global | Allocated size of the global stack 
in bytes | 
| globalused | Number of bytes in use on the 
global stack | 
| globallimit | Size to which the global stack 
is allowed to grow | 
| global_shifts | Number of global stack 
expansions | 
| heapused | Bytes of heap in use by Prolog (0 
if not maintained) | 
| inferences | Total number of passes via the 
call and redo ports since Prolog was started | 
| modules | Total number of defined modules | 
| local | Allocated size of the local stack in 
bytes | 
| local_shifts | Number of local stack 
expansions | 
| locallimit | Size to which the local stack is 
allowed to grow | 
| localused | Number of bytes in use on the 
local stack | 
| table_space_used | Amount of bytes in use by 
the thread's answer tables | 
| trail | Allocated size of the trail stack in 
bytes | 
| trail_shifts | Number of trail stack 
expansions | 
| traillimit | Size to which the trail stack is 
allowed to grow | 
| trailused | Number of bytes in use on the 
trail stack | 
| shift_time | Time spent in stack-shifts | 
| stack | Total memory in use for stacks in all 
threads | 
| predicates | Total number of predicates. This 
includes predicates that are undefined or not yet resolved. | 
| process_epoch | Time stamp when Prolog was 
started | 
| process_cputime | (User) CPU 
time since Prolog was started in seconds | 
| thread_cputime | MT-version: Seconds CPU time 
used by finished threads. Basically non-portable. Works on Linux, 
MacOSX, Windows and probably some more. | 
| threads | MT-version: number of active 
threads | 
| threads_created | MT-version: number of 
created threads | 
| engines | MT-version: number of existing 
engines | 
| engines_created | MT-version: number of 
created engines |