#JSGF V1.0;
grammar SimpleCommands;
public <Command> = <number> | <operators> | <parentheses> | <clear> | <backspace> | <quit> | <toggle> ;

<operators>       = plus | add | minus | subtract | divided by | over | times | multiplied by | equals | squared | cubed | to the power of | exponent | negative;
<parentheses>	  = <direction> <sub>;
<direction> 	  = open | close;
<sub>			  = parentheses;
<number>    	  = [negative] <hundreds> | [negative] <thousands> | [negative] <millions> | [negative] <num>;

<digit>           = one | two | three | four | five | six | seven | eight | nine;

<tens>            = twenty | thirty | forty | fifty | sixty | seventy | eighty | ninety;

<teen> 			  = ten | eleven | twelve | thirteen | fourteen | fifteen | sixteen | seventeen | eighteen | nineteen;

<num> 	  		  = <digit> | <teen> | <tens> | <tens> <digit>;

<hundreds>  	  = <num> Hundred | <num> Hundred [and] <num>;

<thousands>   	  = <num> Thousand | <num> Thousand <num> | <hundreds> Thousand <num> | <hundreds> Thousand | <num> Thousand <hundreds>
	    	      | <hundreds> (Thousand ) <hundreds>;
<millions>   	  = <num> Million | <num> Million <num> | <hundreds> Million <num> | <hundreds> Million | <num> Million <hundreds> 
				  | <hundreds> Million <hundreds> | <num> Million <thousands> | <hundreds> Million <thousands>;

<backspace> = backspace;
<clear> = Clear;
<quit> = quit program;
<toggle> = toggle voice;