<stringname="c_var_description_PI">Ratio of any circle\'s circumference to its diameter. Note: this constant is degree unit dependent => rad: 3.14, deg: 180.0</string>
<stringname="c_var_description_pi">Ratio of any circle\'s circumference to its diameter. Note: this constant is degree unit independent => rad: 3.14, deg: 3.14</string>
<stringname="c_var_description_e">Unique real number such that the value of the derivative (slope of the tangent line) of the function f(x) = e^x at the point x = 0 is equal to 1</string>
<stringname="c_var_description_i">Imaginary unit, defined such that i^2 = −1</string>
<stringname="c_var_description_c">Speed of light in vacuum, m·s^-1</string>
<stringname="c_var_description_G">The gravitational constant is an empirical physical constant involved in the calculation of the gravitational attraction between objects with mass, m^3·kg^−1·s^−2</string>
<stringname="c_var_description_h">Physical constant reflecting the sizes of energy quanta in quantum mechanics, J·s</string>