public InvariantStatus check_modified(long value, int count) {
if (modulus == 1) {
// We shouldn't ever get to this case; the invariant should have been
// destroyed instead.
throw new Error("Modulus = 1");
} else if (no_samples_seen) {
return InvariantStatus.NO_CHANGE;
} else if (value == value1) {
// no new information, so nothing to do
return InvariantStatus.NO_CHANGE;
} else if (modulus == 0) {
// only one value seen so far
// REACHABLE?
if (modulus == 1) {
return InvariantStatus.FALSIFIED;
}
} else {
long new_modulus_long = Math.abs(MathMDE.gcd(modulus, value1 - value));
int new_modulus;
if (new_modulus_long > Integer.MAX_VALUE || (new_modulus_long < Integer.MIN_VALUE)) {
new_modulus = 1;
} else {
new_modulus = (int) new_modulus_long;
assert new_modulus > 0;
}
if (new_modulus != modulus) {
if (new_modulus == 1) {
return InvariantStatus.FALSIFIED;
}
}
}
assert modulus != 1;
return InvariantStatus.NO_CHANGE;
}
public InvariantStatus add_modified(long value, int count) {
if (modulus == 1) {
// We shouldn't ever get to this case; the invariant should have been
// destroyed instead.
throw new Error("Modulus = 1");
// assert falsified;
// // We already know this confidence fails
// return;
} else if (no_samples_seen) {
value1 = value;
no_samples_seen = false;
return InvariantStatus.NO_CHANGE;
} else if (value == value1) {
// no new information, so nothing to do
return InvariantStatus.NO_CHANGE;
} else if (modulus == 0) {
// only one value seen so far
long new_modulus = Math.abs(value1 - value);
if (new_modulus == 1) {
return InvariantStatus.FALSIFIED;
}
modulus = new_modulus;
remainder = MathMDE.mod_positive(value, modulus);
} else {
long new_modulus_long = Math.abs(MathMDE.gcd(modulus, value1 - value));
int new_modulus;
if (new_modulus_long > Integer.MAX_VALUE || (new_modulus_long < Integer.MIN_VALUE)) {
new_modulus = 1;
} else {
new_modulus = (int) new_modulus_long;
assert new_modulus > 0;
}
if (new_modulus != modulus) {
if (new_modulus == 1) {
return InvariantStatus.FALSIFIED;
} else {
remainder = remainder % new_modulus;
modulus = new_modulus;
}
}
}
assert modulus != 1;
return InvariantStatus.NO_CHANGE;
}
protected double computeConfidence() {
if (modulus == 1) return Invariant.CONFIDENCE_NEVER;
if (modulus == 0) {
return Invariant.CONFIDENCE_UNJUSTIFIED;
}
double probability_one_elt_modulus = 1 - 1.0 / modulus;
// return 1 - Math.pow(probability_one_elt_modulus, ppt.num_mod_samples());
return 1 - Math.pow(probability_one_elt_modulus, ppt.num_samples());
}