{n20} factorial(n { c =n; result 1; result n!/c!} while (c>1) resultresult c; C=c-1; } {result=n/c！c=1} return result; } result n! Formal Semantics of Prog.Lang. 09/07/2018factorial( n ) { c = n; result = 1; while (c>1) { result = result * c; c = c-1; } return result; } Formal Semantics of Prog. Lang. 09/07/2018 { result = n!/c!} { result = n!/c!  c=1} { n  0 } { result = n! }