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Unknown eiffel syntax error

variables,eiffel
I am a beginner in Eiffel programming and I just try to create variable and I get an error,heres my code: class APPL create make local v1:BOOLEAN v2:BOOLEAN v3:BOOLEAN do io.putstring ("test") end end I keep getting a "syntax error" on the "local" word...without any details.I'm pretty sure its something...

Prove two algorithms are identical

algorithm,logic,tail-recursion,eiffel
I am supposed to show that two algorithms execute identical statements in identical order. One is a tail recursive version of the other. They are written in Eiffel. tail_rec(x:instance_type):result_type is local y:instance_type; do if b(x) then Result :=c(x) else y:=d(x); Result:=tail_rec(y) end end Then the non-tail recursive version. non_rec(x:instance_type):result_type is...

Proving an algorithm correct by induction

algorithm,correctness,induction,eiffel,proof-of-correctness
I am supposed to prove an algorithm by induction and that it returns 3n - 2n for all n >= 0. This is the algorithm written in Eiffel. P(n:INTEGER):INTEGER; do if n <= 1 then Result := n else Result := 5*P(n-1) - 6*P(n-2) end end My understanding is that...

How to call classes methods in eiffel

function,methods,call,eiffel
im kind of a beginner in eiffel,and I got 2 classes, the main one called APPLICATION that contain this: class APPLICATION inherit ARGUMENTS create make feature {NONE} -- Initialization make -- Run application. do print ("test") end end and another classe called BLUE: class BLUE create make feature make local...