INVARIENT EXAMPLE

// invarient: we have written r rows so far

int r = 0;

// setting r to 0 makes the invarient true

while (r != rows) {

// we can asume that the invarient is true here

// writing a row of output makes the invarient false

cout << endl;

// incrementing r makes the invarient true again

++ r;

}

// we can conclude that the invarient is true here