How to fuzify a crispy variable - clips

Question

I read some examples about how to fuzify a variable in FuzzyClips. I tried it by myself but i got some strange behaviour:
(deftemplate age-template
0 100 years ; Universe
(
(young (15 0.75) (17 1) (19 1))
(mature (18 0.75) (25 1) (30 0.25))
(adult (30 0.5) (40 1) (50 0.75))
(old (40 0.25) (50 0.75) (65 1) )
)
)
(deftemplate person
(slot name (type STRING))
(slot age (type INTEGER))
(slot city (type STRING))
)
(deffacts start
(person (name "John") (age 25) (city "London"))
(person (name "Mike") (age 55) (city "London"))
(person (name "Eva") (age 35) (city "London"))
)
(defrule fuzzify
(person (name ?name) (age ?age))
=>
(assert(age-template (?age 0.0) (?age 1.0) (?age 0.0)))
)
I don't know exactly what those "???" really mean and why each fact is being retracted after being asserted. I also have another doubt, i tried to print not only the age, but also the name and the age of each person with:
(defrule fuzzify
(person (name ?name)(age ?age))
=>
(assert (person-is ?name age-template (?age 0.0) (?age 1.0) (?age 0.0)))
)
But i got error "a function name must be a symbol".

Answer 1

So i solved it. I read that getting ??? is a common behaviour. So the solution is:
Create another deftemplate that will be the structure of the person name with their fuzzy age. In the rule's consecuent, instanciate the deftemplate asserting someone's name with the fuzzy age.
(deftemplate age-template
0 100 years ; Universe
(
(young (15 0.75) (17 1) (19 1))
(mature (18 0.75) (25 1) (30 0.25))
(adult (30 0.5) (40 1) (50 0.75))
(old (40 0.25) (50 0.75) (65 1) )
)
)
(deftemplate person
(slot name (type STRING))
(slot age (type INTEGER))
(slot city (type STRING))
)
(deftemplate fuzzyfication
(slot nameperson (type STRING))
(slot agefuzzy (type FUZZY-VALUE age-template))
)
(deffacts start
(person (name "John") (age 25) (city "London"))
(person (name "Mike") (age 55) (city "London"))
(person (name "Eva") (age 35) (city "London"))
)
(defrule fuzzify
(person (name ?name) (age ?age))
=>
(assert(fuzzyfication (nameperson ?name)(agefuzzy (?age 0.0) (?age 1.0) (?age 0.0))))
)
And the execution returns: