B737 CROSSED RWY HOLD LINE AT BOI WHILE TAXIING TO ASSIGNED RWY AS GA ACFT LANDED.

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TAXI OUT INSTRUCTIONS WERE: 'TAXI TO RWY 10R; CROSS RWY 10L AT TXWY G; STAY WITH ME FOR FULL LENGTH.' RWY 10L WAS CLOSED; ALONG WITH MULTIPLE TXWYS. CTLR APPARENTLY MEANT TO SAY; 'HOLD SHORT OF RWY 10R AT TXWY G.' WE PLANNED TO CROSS RWY 10R AT TXWY G AND TAXI TO THE APCH END OF TXWY J; AS WE HAD BEEN IMPLICITLY CLRED. BEFORE WE CROSSED RWY 10R; WE SAW A SMALL ACFT ON 3/4 MI FINAL FOR RWY 10R AND THE CAPT STOPPED THE ACFT WELL SHORT OF THE RWY BUT PAST THE HOLD SHORT LINE. GND THEN TOLD US TO HOLD SHORT OF RWY 10R. THE CESSNA LANDED ON RWY 10R (WE WERE WELL CLR OF THE RWY BUT PAST THE HOLD SHORT LINE). THE CAUSE OF THE INCURSION WAS POOR CTLR LANGUAGE; NAMELY: FAILURE TO STATE HOLD SHORT INSTRUCTIONS. WE FOLLOWED COMPANY PROCS AND COMMON SENSE BY VISUALLY CHKING FINAL FOR TFC BEFORE XING. WE TECHNICALLY INCURRED THE RWY BY XING THE HOLD SHORT LINE; BUT STOPPED PRIOR TO ENTERING THE RWY; NEVER CAUSING AN UNSAFE SITUATION. TO PREVENT FUTURE OCCURRENCES; I WILL MAKE SURE I CHK FOR TFC WELL BEFORE XING THE HOLD SHORT LINE; TO BE 'LEGAL' AS WELL AS 'SAFE.' ALSO; INCREASED VIGILANCE IS REQUIRED AT ARPTS WITH MORE GA TFC LIKE BOISE. THE SMALL SIZE OF THE CESSNA MADE IT MUCH HARDER TO SEE THAN THE EXPECTED AIRLINER.