"""Hypothetical arithmetic only: no device I/O or circuit simulation."""
from math import isclose
ref,light,batt=675,205,376
assert isclose(3.3*light/ref,1.0022222222222221)
assert isclose(3.3*batt/ref*4.9,9.007288888888889)
assert isclose(9/4.9,1.8367346938775508)
assert isclose((9-3.3)*.05,.285)
assert isclose(.285*220,62.7)
assert isclose(.8473*4700*100e-12,398.231e-9)
assert isclose(3.3/3.25-1,.01538461538461533)
assert isclose(99850/100,998.5)
lo=4.9/(1+3900*1.01/(1000*.99))-1
hi=4.9/(1+3900*.99/(1000*1.01))-1
assert -.0161<lo<-.0157 and .0158<hi<.0162
print("9 arithmetic checks passed; no hardware, sensor or weather simulation")