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		Welcome to my CalThon Language!
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		CalThon allows you to perform basic arithmetic.
        The language generates a smart message if its syntax is not followed.

        - add by using a statement:       ADD N1 AND N2
        - subtract by using a statement:  SUB N2 FROM N1
        - multiply by using a statement:  MUL N1 BY N2 
        - divide by using a statement:    DIV N1 BY N2
        	
        Note:
        - N1 and N2 are operands - any numbers you wish.
        - ADD, SUB, MUL and DIV are four operators.
        - AND, FROM, and BY are three keywords.
        - Operators and keywords can be lowercase or mixed case. 
        - N2 should not be zero if the operation is DIV!
        	
        The equation you enter must follow this syntax:
        <operator><space><operand><space><keyword><space><operand>
        A <space> is a white space character.
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Enter an arithmetic statement or 'Q' or 'q' to Quit the Calculator: ADD 10 AND 20

Answer: ADD 10 AND 20 = 30
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Enter an arithmetic statement or 'Q' or 'q' to Quit the Calculator: SUB 50 FROM 70

Answer: SUB 50 FROM 70 = 20
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Enter an arithmetic statement or 'Q' or 'q' to Quit the Calculator: MUL 15 BY 10

Answer: MUL 15 BY 10 = 150
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Enter an arithmetic statement or 'Q' or 'q' to Quit the Calculator: DIV 150 BY 10

Answer: DIV 150 BY 10 = 15
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Enter an arithmetic statement or 'Q' or 'q' to Quit the Calculator: q

Bye!