How are values passed in F# for Functions? -

it first day of learning f#. going through tryfsharp.org when came across following example topic functions values

let christest test =  test "chris" let isme x =  if x = "chris"     "it chris!"  else     "it's else" christest isme 

explanation on site:- christest simple higher order function executes test against string value. isme function checks see if string equal "chris". passing ischris christest passes string "chris" argument `ischris" function, , returns result of "it chris!".

my thought:- value of isme function passed function christest in last line of program. not there no value passed isme function. how isme function decide execute value return?

for case can start replacing in christest. have

christest isme = isme "chris" (as test=isme) 

and rest follows similar procedure