def check_exists(fips_dir=None) :
    try :
        subprocess.check_output(['git', '--version'])
        return True
    except (OSError, subprocess.CalledProcessError) :
        return False

#-------------------------------------------------------------------------------
Determines whether solutions returned by diophantine() satisfy the original
dataset/ETHPy150Open floooh/fips/mod/tools/git.py/check_exists--crossover with--dataset/ETHPy150Open sympy/sympy/sympy/solvers/tests/test_diophantine.py/check_solutions