The help files:
MAKE MATRIX : MAKE MATRIX Matrix Number, Width, Height, XSegments, ZSegments
DELETE MATRIX : DELETE MATRIX Matrix Number
PREPARE MATRIX TEXTURE : PREPARE MATRIX TEXTURE Matrix Number, Image Number, Across, Down
POSITION MATRIX : POSITION MATRIX Matrix Number, X, Y, Z
FILL MATRIX : FILL MATRIX Matrix Number, Height, Tile Number
RANDOMIZE MATRIX : RANDOMIZE MATRIX Matrix Number, Maximum Height
GHOST MATRIX ON : GHOST MATRIX ON Matrix Number
GHOST MATRIX OFF : GHOST MATRIX OFF Matrix Number
SET MATRIX WIREFRAME ON : SET MATRIX WIREFRAME ON Matrix Number
SET MATRIX WIREFRAME OFF : SET MATRIX WIREFRAME OFF Matrix Number
SET VECTOR3 TO MATRIX POSITION : SET VECTOR3 TO MATRIX POSITION Vector, Matrix Number
SET MATRIX TEXTURE : SET MATRIX TEXTURE Matrix Number, Texture Mode, Mip Mode
SET MATRIX : SET MATRIX Matrix Number, Wire, Transparency, Cull, Filter, Light, Fog, Ambient
SET MATRIX TRIM : SET MATRIX TRIM Matrix Number, TrimX, TrimY
SET MATRIX PRIORITY : SET MATRIX PRIORITY Matrix Number, Priority Flag
SHIFT MATRIX DOWN : SHIFT MATRIX DOWN Matrix Number
SHIFT MATRIX LEFT : SHIFT MATRIX LEFT Matrix Number
SHIFT MATRIX RIGHT : SHIFT MATRIX RIGHT Matrix Number
SHIFT MATRIX UP : SHIFT MATRIX UP Matrix Number
SET MATRIX HEIGHT : SET MATRIX HEIGHT Matrix Number, TileX, TileZ, Height
SET MATRIX NORMAL : SET MATRIX NORMAL Matrix Number, TileX, TileZ, NX, NY, NZ
SET MATRIX TILE : SET MATRIX TILE Matrix Number, TileX, TileZ, Tile Number
UPDATE MATRIX : UPDATE MATRIX Matrix Number
MATRIX EXIST : Return Integer=MATRIX EXIST(Matrix Number)
MATRIX POSITION X : Return Float=MATRIX POSITION X(Matrix Number)
MATRIX POSITION Y : Return Float=MATRIX POSITION Y(Matrix Number)
MATRIX POSITION Z : Return Float=MATRIX POSITION Z(Matrix Number)
MATRIX TILE COUNT : Return Integer=MATRIX TILE COUNT(Matrix Number)
MATRIX TILES EXIST : Return Integer=MATRIX TILES EXIST(Matrix Number)
MATRIX WIREFRAME STATE : Return Integer=MATRIX WIREFRAME STATE(Matrix Number)
GET GROUND HEIGHT : Return Float=GET GROUND HEIGHT(Matrix Number, X, Z)
GET MATRIX HEIGHT : Return Float=GET MATRIX HEIGHT(Matrix Number, TileX, TileZ)
Immunity and Annihalation makes Immunihalation...