HP 49g Graphing Calculator - Manual (Page 182)

Example: Substitute X = z+l for X in the following expression, and
apply the EXPAND command to simplify the result:
+ 3x + l
Command: S U B S T { X - ' 2 + 3 * X + 7 , X = Z + 1 )
E X P A N D ( A N S ( 1 )
)
Result: Z " 2 + 5 * Z + 1 1
SUBTMOD
Type: Function
Description: Performs a subtraction, modulo the current modulus.
Access: Arithmetic, 0 ® B MODULO
Input: Level 2/Argument 1: The object or number to be
subtracted from.
Level 1/Argmnent 2: The object or number to subtract.
Output: The result of the subtraction, modulo the current
modulus.
Flags: Exact mode must be set (flag -105 clear).
Numeric mode must not be set (flag -03 clear).
SYLVESTER
Type: Command
Description: For a symmetric matrix A, returns D and P where D is a
diagonal matrix and
A = P'^DP
Access: Catalog, ®
Input: A synunetric matrix.
Output: Level 2/Item 1: the diagonal matrix, D.
Level 1 1/Item 2: The matrix P.
Flags: Exact mode must be set (flag -105 clear).
Numeric mode must not be set (flag -03 clear).
Computer Algebra Commands Page 14-59