[Dev-C++] undefined reference...

[<tc...@gm...>]

Hi...
Can somebody help me please to interpret the undefined reference error 
message?
I have created a c++ library, but trying to use it with any client 
program fails with the undefined reference error. First I thought It may 
lay on my program, but realized later that linking other libs throw me 
the same kinds of error too...

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Eric Tchepannou