Propagator is a tool used to calculate the uncertainty of an expression. The output is the variance, denoted as σ². The standard deviation, σ, is the square root of the variance.

Grammar

• Operations: + , - , * , / , ^
• Functions: exp( ) , ln( ), log10( ), sqrt( ), 1e10, 1e-6
• Numbers: 10 * var1, 20 + var2, ...
• Constants: for the variables without uncertainty, use the prefix cst_: cst_rho, cst_k
• Unlimited parenthesis pairs: 7 * ( var1 * ( 4 * ( ... ) + var2 ) + exp(var4) )