nl_tokens: integral ( + / - f ( x ) x ) = + / - integral ( f ( x ) x ) and integral ( f ( x ) + / - g ( x ) x ) = integral ( f ( x ) x ) + / - integral ( g ( x ) x )
pl_tokens: function ( expr , context , subIntegral ) { if ( expr . <mask> === "OperatorNode" && ( expr . op === '+' || expr . op === '-' ) ) { var childInts = expr . args . map ( function ( expr ) { return subIntegral ( expr , context , "sum rule" ) ; } ) ; if ( childInts . every ( function ( n ) { return n ; } ) ) { return new OperatorNode ( expr . op , expr . fn , childInts ) ; } } }