#define twopi 6.2831853071795864769252867665590057684
dim shared as double S = 0     'set up the state as a global variable
dim shared as double t0, t1, ta

function sine( x as double, f as double ) as double
    return sin(twopi*f*x)
end function

function zero( x as double, f as double ) as double
    return 0
end function

sub integrate( K as function(as double, as double) as double, f as double )
    'represent input as pointers to functions
    t1 = timer
    s += (K(t1,f) + K(t0,f))*(t1-t0)/2.0
    t0 = t1
end sub

t0 = timer
ta = timer

while timer-ta <= 2.5
    if timer-ta <= 2 then integrate( @sine, 0.5 ) else integrate( @zero, 0 )
wend

print S