FUNCTION dot (a(), b())
    IF UBOUND(a) <> UBOUND(b) THEN LET dot = 0
    LET dp = 0.0
    FOR i = LBOUND(a) TO UBOUND(a)
        LET dp = dp + (a(i) * b(i))
    NEXT i
    LET dot = dp
END FUNCTION

DIM zero3d(3)
LET zero3d(1) = 0.0
LET zero3d(2) = 0.0
LET zero3d(3) = 0.0
DIM zero5d(5)
LET zero5d(1) = 0.0
LET zero5d(2) = 0.0
LET zero5d(3) = 0.0
LET zero5d(4) = 0.0
LET zero5d(5) = 0.0
DIM x(3)
LET x(1) = 1.0
LET x(2) = 0.0
LET x(3) = 0.0
DIM y(3)
LET y(1) = 0.0
LET y(2) = 1.0
LET y(3) = 0.0
DIM z(3)
LET z(1) = 0.0
LET z(2) = 0.0
LET z(3) = 1.0
DIM q(3)
LET q(1) = 1.0
LET q(2) = 1.0
LET q(3) = 3.14159
DIM r(3)
LET r(1) = -1.0
LET r(2) = 2.618033989
LET r(3) = 3.0

PRINT " q dot r           = "; dot(q(), r())
PRINT " zero3d dot zero5d = "; dot(zero3d(), zero5d())
PRINT " zero3d dot x      = "; dot(zero3d(), x())
PRINT " z dot z           = "; dot(z(), z())
PRINT " y dot z           = "; dot(y(), z())
END