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<ng-container *ngIf="condition_01; then then_01; else else_01"></ng-container>
<ng-template #then_01>
<ng-container *ngIf="condition_02; then then_02; else else_02"></ng-container>
<ng-template #then_02>
<div>Then 02 block content</div>
</ng-template>
<ng-template #else_02>
<div>Else 02 block content</div>
</ng-template>
</ng-template>
<ng-template #else_01>
<div>Else 01 block content</div>
</ng-template>
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<ng-container *ngIf="(value1 || value2); else showDefault">
<ng-container *ngIf="value3!=null && value4==null; else showValue4">
</ng-container>
<ng-template #showValue4>
</ng-template>
</ng-container>
<ng-template #showDefault>
</ng-template>