string restrictions and pattern matching

gistfile1.txt

Here is a question gapfill part on prime factorisation, pi primes, ei their exponents. 
Awful business trapping student input. 
So much better if there were restrictions that said that the primes (without 0 exponent) had to be present in the answer.


gaps: [
					{type: jme 
					answer: "{p1}^{e1}*{p2}^{e2}*{p3}^{e3}*{p5}^{e5}"
					answersimplification:"unitPower,zeroPower,unitFactor"
					musthave:{
						strings:[*,^]
						message:"split into factors, each factor a power of a prime number and include the multiplication sign * between the factors "
						}
					notallowed:{
						strings:["1^","1*",*1",/,"-","^0"]
						message: "split into factors, each factor a power of a prime number and include the multiplication sign * between the factors"
						}
					minlength:{length:11}
					marks:1
					
					}
						]