1.b> i> , i> ; the interchange of letters in a word ;
2.b> i> ; the interchange of letters , ; the interchange of gifts i> ; the interchange of opinions i> / ; the interchange of greetings ; the interchange of civilities ; to establish an interchange of commodities between two countries ;
3.b> ; the interchange of light and darkness ; the interchange of hills and valleys ;
interchange point .-.i> i> / .