00 { 37-Byte Prgm }
01▸LBL "FAC"
02 X≠0?
03 GTO 00
04 SIGN
05 RTN
06▸LBL 00
07 R↑
08 LSTO "T"
09 R↓
10 LSTO "N"
11 1
12 -
13 XEQ "FAC"
14 RCL "N"
15 ×
16 RCL "T"
17 R↓
18 END